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From page 106... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 106 Appendices Table of Contents A Read the entire page →
From page 107... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 107 H Read the entire page →
From page 108... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 108 List of Tables Table A-1. Average Ranking Score for Performance Measures ................................................ Read the entire page →
From page 109... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 109 Table F-2. Coefficients Used in Speed-Flow Slope Model (Equation (F-4) Read the entire page →
From page 110... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 110 List of Figures Figure A-1. Agency Survey on Performance Measures ......................................................................... Read the entire page →
From page 111... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 111 Figure D-13. Percent follower-flow curves for passing zone with 10 percent heavy vehicles in analysis direction. Read the entire page →
From page 112... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 112 Figure D-31. Performance measure-flow relationships for a vertical class 3, passing lane segment. Read the entire page →
From page 113... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 113 Figure F-11. Distribution of residuals from the speed-flow slope coefficient model by vertical alignment classification. Read the entire page →
From page 114... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 114 Figure I-7. Simulation Button on Toolbar ..................................................................................538 Figure I-8. Read the entire page →
From page 115... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 115 A Current Agency Practices and Preferences In order to better understand the transportation agencies' perception and preferences with regard to performance measures on two-lane highways, an online survey was designed as part of the NCHRP Project 17-65. Read the entire page →
From page 116... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 116 another measure introduced by the South African National Roads Agency and is calculated as the product of percent followers (PF) , defined earlier, and traffic density (Van As and Niekerk, 2004) Read the entire page →
From page 117... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 117 Read the entire page →
From page 118... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 118 Read the entire page →
From page 119... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 119 Read the entire page →
From page 120... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 120 Read the entire page →
From page 121... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 121 Read the entire page →
From page 122... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 122 Read the entire page →
From page 123... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 123 Read the entire page →
From page 124... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 124 Read the entire page →
From page 125... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 125 Read the entire page →
From page 126... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 126 Figure A-1. Agency Survey on Performance Measures Read the entire page →
From page 127... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 127 A.2. Survey Responses A total of 41 responses were received, representing transportation agencies at 25 states and 4 Canadian provinces. Read the entire page →
From page 128... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 128 A.3.1. Agency Practice Use of Current HCM Methodology When asked about the use of HCM 2010 methodology for two-lane highways, all responding agencies in the U.S. Read the entire page →
From page 129... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 129 Data Collected In Support of Performance Measurement on Two-Lane Highways The survey asked participants about the data collected by their respective agencies that is used in assessing performance on two-lane highways. The results are summarized in Figure A-4. Read the entire page →
From page 130... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 130 As shown in this figure, the most important characteristic in a two-lane highway performance measure is being sensitive to traffic conditions, as perceived by survey participants. The second characteristic in importance is being sensitive to road conditions. Read the entire page →
From page 131... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 131 Figure A-6. Average ranking score of traffic flow aspects As Figure A-6 depicts, speed was ranked as the most useful aspect of traffic flow in assessing performance on two-lane highways. Read the entire page →
From page 132... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 132 Table A-1. Average Ranking Score for Performance Measures Traffic Flow Aspect Performance Measure Average Ranking Score Class I Class II Class III Flow Volume-to-Capacity (v/c) Read the entire page →
From page 133... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 133 While Table A-1 is useful in comparing performance measures that belong to the same group/category, it cannot be used to provide objective comparisons across categories. Specifically, the number of measures in each group is different, and therefore, the same average ranking in two different groups could indicate different levels of merit. Read the entire page →
From page 134... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 134 included a few questions about the agency experience with the use of the HCM and proposed changes and revisions to the current analytical procedures. A total of 35 usable responses were received, representing transportation agencies at 25 states and 4 Canadian provinces. Read the entire page →
From page 135... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 135 B Service Measure Evaluation B.1. Read the entire page →
From page 136... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 136 measures) , namely: percent time spent following (PTSF) Read the entire page →
From page 137... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 137 several miles long, there could be many changing conditions, such as posted speed limit and roadway alignment that affect ATS, yet it is not related to varying traffic conditions. In this section, a review of alternative performance measures that have been proposed in the literature or reported as part of current practice is presented. Read the entire page →
From page 138... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 138 In their article on the German experience, Brilon and Weiser (2006) reported the use of average speed of passenger cars over a longer stretch of highway, averaged over both directions, as a major performance measure on two-lane highways. Read the entire page →
From page 139... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 139 The most commonly used headway-based service measure is percent followers (PF) Read the entire page →
From page 140... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 140 B.3.5. Combination Measures A couple of measures proposed in the literature are associated with more than one traffic stream parameter, and as such, they are discussed independently from the previous measures. Read the entire page →
From page 141... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 141 • This criterion may be hard to satisfy as it is expected that different aspects of traffic operations are perceived as most important by drivers on different highway facilities. For example, while platooning on two-lane highways is a major determinant of the quality of operation, it is not a major factor in determining the quality of operations on other facilities. Read the entire page →
From page 142... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 142 Table B-1. Preliminary assessment matrix of performance measures on two-lane highways Performance Measure Type a (1) Read the entire page →
From page 143... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 143 B.5. Empirical Analysis of Field Data This section presents an empirical investigation into several two-lane highway performance measures that have been used in practice or proposed in the literature for operational analysis on two lane highways. Read the entire page →
From page 144... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 144 • Combined flow (veh/h) : The hourly flow rate in both directions of travel. Read the entire page →
From page 145... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 145 6. ATR 44, Highway U.S. Read the entire page →
From page 146... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 146 16. Site 17-OR, Highway U.S. Read the entire page →
From page 147... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 147 Table B-2. Description of Field Data at Study Sites Site name Dates Class Duration of data collection (hours) Read the entire page →
From page 148... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 148 ATR 28 ATR 43 ATR 73 ATR 132 Figure B-1. Montana data collection sites ATR 47 ATR 147 ATR 44 ATR 126 Figure B-2. Read the entire page →
From page 149... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 149 Site 17 Site 13 Site 2 Site 11 Figure B-3. Oregon data collection sites Site 1 Site 7 Site 4 Site 3 Figure B-4. Read the entire page →
From page 150... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 150 B.5.3. Research Underlying Hypotheses In this section, the major hypotheses underlying the relationship between performance measures and traffic variables are discussed. Read the entire page →
From page 151... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 151 performance measures investigated in this study and combined flow (combined flow in the two directions of travel) Read the entire page →
From page 152... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 152 Figure B-5. Scatterplots of performance measures vs combined flow Read the entire page →
From page 153... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 153 Figure B-6. Scatterplots of performance measures vs traffic split Read the entire page →
From page 154... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 154 Figure B-7. Scatterplots of performance measures vs speed variance Read the entire page →
From page 155... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 155 Figure B-8. Scatterplots of performance measures vs percent heavy vehicles Read the entire page →
From page 156... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 156 Correlation and Regression Analyses To get a better insight into the suitability of performance measures on different types of two-lane highways, three levels of analysis (data aggregation) were used in this study. Read the entire page →
From page 157... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 157 • Percent heavy vehicles exhibited very low correlation coefficients with all performance measures. • Again, headway-related performance measures generally exhibited high correlations with combined flow with coefficients greater than 0.8 for FD, FF, ID and IF. Read the entire page →
From page 158... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 158 Table B-5. Correlation analysis results for Class II data (1465 observations) Read the entire page →
From page 159... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 159 Table B-6. Correlation analysis results for Class III data (2294 observations) Read the entire page →
From page 160... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 160 Table B-7. Results from Multivariate Linear Regression Analysis for combined data Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split Percent HV Speed Variance Percent no passing Regression results for combined data ATS 0.10 5.55 63.41 0.00 –0.007 0.00 –2.25 0.00 –0.03 0.00 0.007 0.00 –0.01 0.00 ATS/FFS 0.06 0.02 1.008 0.00 –0.00002 0.00 –0.01 0.00 –0.0003 0.00 –0.00002 0.00 -- - % Follower 0.63 10.44 –4.45 0.00 0.06 0.00 26.9 0.00 0.12 0.00 -- - –0.13 0.00 Follower Flow 0.79 33.82 –94.33 0.00 0.27 0.00 127.22 0.00 0.16 0.00 –0.02 0.00 –0.15 0.00 Follower Density 0.79 0.6 –1.69 0.00 0.005 0.00 2.25 0.00 0.003 0.00 –0.0004 0.00 –0.0002 0.00 % Impeded 0.55 7.67 –2.96 0.00 0.03 0.00 16.49 0.00 0.08 0.00 0.004 0.00 –0.08 0.00 Impeded Flow 0.75 23.24 –58.07 0.00 0.17 0.00 77.42 0.00 0.12 0.00 –0.007 0.04 –0.08 0.00 Impeded Density 0.74 0.42 –1.05 0.00 0.003 0.00 1.38 0.00 0.002 0.00 –0.0001 0.01 –0.001 0.00 -Values in bold are inconsistent with the hypothesized logical relationship. Read the entire page →
From page 161... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 161 Table B-8. Results from Multivariate Linear Regression Analysis for class I sites Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split Percent HV Speed Variance Class 1 ATS 0.13 4.8 64.59 0.00 –0.007 0.00 –3.06 0.00 –0.03 0.00 0.004 0.00 ATS/FFS 0.08 0.02 1.01 0.00 –0.00002 0.00 –0.01 0.00 –0.0004 0.00 –0.00001 0.00 % Follower 0.57 11.49 –7.23 0.00 0.05 0.00 29.39 0.00 0.07 0.00 –0.008 0.00 Follower Flow 0.79 36.08 –118.37 0.00 0.29 0.00 163.67 0.00 -- - –0.03 0.00 Follower Density 0.79 0.64 –2.09 0.00 0.005 0.00 2.85 0.00 -- - –0.0005 0.00 % Impeded 0.48 8.41 –4.69 0.00 0.03 0.00 17.24 0.00 0.07 0.00 -- - Impeded Flow 0.75 25.04 –72.15 0.00 0.18 0.00 98.1 0.00 0.06 0.007 –0.01 0.00 Impeded Density 0.73 0.45 –1.29 0.00 0.003 0.00 1.72 0.00 0.001 0.01 –0.0002 0.00 -Values in bold are inconsistent with the hypothesized logical relationship. Read the entire page →
From page 162... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 162 Table B-10. Results from Multivariate Linear Regression Analysis for class III sites Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split Percent HV Speed Variance Class 3 ATS 0.03 6.74 60.72 0.00 –0.003 0.00 –5.06 0.00 –0.08 0.00 –0.02 0.03 ATS/FFS 0.11 0.01 1.009 0.00 –0.00001 0.00 –0.01 0.00 0.00007 0.03 0.0002 0.00 % Followers 0.75 7.9 –12.18 0.00 0.05 0.00 29.91 0.00 0.08 0.00 –0.04 0.00 Follower Flow 0.81 30.6 –110.86 0.00 0.25 0.00 144 0.00 0.66 0.00 –0.09 0.008 Follower Density 0.80 0.55 –2.09 0.00 0.004 0.00 2.75 0.00 0.01 0.00 -- - % Impeded 0.63 6.15 –8.61 0.00 0.03 0.00 19.52 0.00 0.05 0.001 -- - Impeded Flow 0.76 20.76 –68.72 0.00 0.15 0.00 90.38 0.00 0.39 0.00 -- - Impeded Density 0.76 0.38 –1.29 0.00 0.003 0.00 1.73 0.00 0.008 0.00 -- - -Values in bold are inconsistent with the hypothesized logical relationship. Read the entire page →
From page 163... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 163 Table B-12. Performance measures rank by class using R2 Performance Measure Sites Class I Class II Class III Rank Regression model R2 Rank Regression model R2 Rank Regression model R2 ATS 7 0.13 7 0.25 8 0.03 ATS/FFS 8 0.08 8 0.04 7 0.11 % Followers 5 0.57 5 0.27 5 0.75 Follower Flow 1 0.79 1 0.54 1 0.81 Follower Density 1 0.79 2 0.51 2 0.80 % Impeded 6 0.48 6 0.25 6 0.63 Impeded Flow 3 0.75 3 0.50 3 0.76 Impeded Density 4 0.73 4 0.48 4 0.76 Table B-13 shows performance measure rankings by R2 value using site-specific regression results. Read the entire page →
From page 164... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 164 Table B-14. Number of times variable found significant using site specific regression runs Performance Measure Combined Flow Traffic Split % Trucks Speed Variance ATS 15 8 8 14 ATS/FFS 14 7 4 14 % Follower 16 16 8 4 Follower Flow 16 16 5 5 Follower Density 16 16 5 5 % Impeded 16 16 9 10 Impeded Flow 16 16 5 8 Impeded Density 16 16 5 12 Table B-15 shows the number of times traffic variables were found significant for each performance measure using highway class regression runs. Read the entire page →
From page 165... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 165 B.6. Summary The results from the empirical analysis demonstrated that across all highway classes, follower density and follower flow had the highest correlation among several traffic variables. Read the entire page →
From page 166... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 166 B.6.1. Site Specific Regression Results (Class I) Read the entire page →
From page 167... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 167 Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance ATR 44 ID ATS 0.29 1.48 64.43 0.00 –0.002 0.00 1.2 0.003 -- - –0.03 0.00 ATS/FFS 0.13 0.01 1.009 0.00 –0.00002 0.00 –0.009 0.007 –0.0001 0.008 –0.00007 0.00 % Follower 0.71 7.14 –10.06 0.00 0.07 0.00 23.05 0.00 -- - -- - Follower Flow 0.83 15.9 –72.09 0.00 0.22 0.00 100.67 0.00 -- - 0.04 0.001 Follower Density 0.82 0.26 –1.16 0.00 0.003 0.00 1.6 0.00 -- - 0.0001 0.00 % Impeded 0.64 5.99 –7.65 0.00 0.05 0.00 14.96 0.00 -- - 0.02 0.00 Impeded Flow 0.77 12.97 –49.98 0.00 0.15 0.00 67.19 0.00 -- - 0.06 0.00 Impeded Density 0.76 0.21 –0.81 0.00 0.002 0.00 1.07 0.00 -- - 0.001 0.00 -Values in bold are inconsistent with the hypothesized logical relationship. Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance ATR 47 ID ATS 0.42 1.23 57 0.00 –0.004 0.00 -- - 0.01 0.03 –0.04 0.00 ATS/FFS 0.02 0.01 1.002 0.00 –0.000007 0.001 -- - -- - 0.00004 0.03 % Follower 0.69 6 –9.81 0.00 0.04 0.00 33.45 0.00 –0.08 0.007 –0.04 0.00 Follower Flow 0.85 18.14 –127.56 0.00 0.2 0.00 198.34 0.00 -- - –0.05 0.04 Follower Density 0.85 0.35 –2.43 0.00 0.004 0.00 3.7 0.00 -- - -- - % Impeded 0.61 4.8 –7.01 0.00 0.03 0.00 20.9 0.00 –0.05 0.04 –0.02 0.00 Impeded Flow 0.80 13.94 –82.17 0.00 0.13 0.00 124.26 0.00 -- - -- - Impeded Density 0.79 0.27 –1.56 0.00 0.002 0.00 2.32 0.00 -- - -- - -Values in bold are inconsistent with the hypothesized logical relationship. Read the entire page →
From page 168... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 168 Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 2-OR ATS 0.32 2.03 69.44 0.00 –0.006 0.00 –3.88 0.00 –0.06 0.00 –0.02 0.00 ATS/FFS 0.26 0.02 1.009 0.00 –0.00003 0.00 -- - -- - –0.0001 0.00 % Follower 0.63 9.13 -- - 0.08 0.00 19.47 0.00 -- - -- - Follower Flow 0.87 15.37 –65.04 0.00 0.28 0.00 80.15 0.00 -- - -- - Follower Density 0.86 0.26 –1.1 0.00 0.004 0.00 1.31 0.00 -- - -- - % Impeded 0.47 8.06 -- - 0.05 0.00 9.02 0.02 -- - 0.04 0.00 Impeded Flow 0.76 13.64 –40.07 0.00 0.16 0.00 42.91 0.00 -- - 0.05 0.009 Impeded Density 0.75 0.23 –0.68 0.00 0.003 0.00 0.71 0.00 -- - 0.0009 0.001 -Values in bold are inconsistent with the hypothesized logical relationship. Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 11-OR ATS 0.24 1.76 66.63 0.00 –0.005 0.00 –1.94 0.02 -- - –0.02 0.00 ATS/FFS 0.12 0.01 1.006 0.00 -- - -- - -- - –0.0001 0.00 % Follower 0.60 8.05 –12.58 0.00 0.07 0.00 33.85 0.00 -- - -- - Follower Flow 0.75 14.69 –49.27 0.00 0.19 0.00 69.88 0.00 -- - -- - Follower Density 0.75 0.23 –0.80 0.00 0.003 0.00 1.11 0.00 -- - -- - % Impeded 0.47 6.47 –8.64 0.00 0.04 0.00 19.6 0.00 -- - 0.04 0.006 Impeded Flow 0.69 10.22 –29.5 0.00 0.11 0.00 39.03 0.00 -- - -- - Impeded Density 0.68 0.16 –0.48 0.00 0.002 0.00 0.62 0.00 -- - 0.0008 0.02 -Values in bold are inconsistent with the hypothesized logical relationship. Read the entire page →
From page 169... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 169 Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 13-OR ATS 0.44 4.44 63.35 0.00 0.01 0.00 –8.51 0.001 –0.03 0.03 –0.03 0.00 ATS/FFS 0.28 0.06 1.07 0.00 -- - -- - –0.0007 0.00 –0.0002 0.00 % Follower 0.52 10.49 –18.47 0.00 0.07 0.00 19.92 0.001 0.36 0.00 0.03 0.001 Follower Flow 0.67 11.43 –44.72 0.00 0.17 0.00 44.48 0.00 0.32 0.00 -- - Follower Density 0.65 0.23 –0.9 0.00 0.003 0.00 0.9 0.00 0.006 0.00 0.0005 0.008 % Impeded 0.51 7.64 –12.02 0.00 0.05 0.00 11.27 0.007 0.22 0.00 0.03 0.00 Impeded Flow 0.65 8.88 –32.47 0.00 0.12 0.00 30.72 0.00 0.21 0.00 0.02 0.009 Impeded Density 0.65 0.17 –0.65 0.00 0.002 0.00 0.62 0.00 0.004 0.00 0.0005 0.00 -Values in bold are inconsistent with the hypothesized logical relationship. Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 17-OR ATS 0.20 2.01 65.48 0.00 0.001 0.03 -- - –0.05 0.00 –0.01 0.002 ATS/FFS 0.47 0.01 1.03 0.00 –0.00004 0.00 –0.03 0.00 –0.0001 0.006 –0.0002 0.00 % Follower 0.74 7.58 –19.2 0.00 0.05 0.00 36.62 0.00 0.13 0.00 -- - Follower Flow 0.75 33.62 –123.17 0.00 0.24 0.00 165.6 0.00 0.58 0.00 -- - Follower Density 0.75 0.53 –1.95 0.00 0.004 0.00 2.6 0.00 0.009 0.00 -- - % Impeded 0.67 5.51 –12.86 0.00 0.03 0.00 20.41 0.00 0.08 0.001 0.03 0.004 Impeded Flow 0.67 25.62 –79.23 0.00 0.15 0.00 97.1 0.00 0.41 0.00 -- - Impeded Density 0.66 0.41 –1.26 0.00 0.002 0.00 1.52 0.00 0.007 0.00 -- - -Values in bold are inconsistent with the hypothesized logical relationship. Read the entire page →
From page 170... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 170 Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 1-NC ATS 0.16 1.82 61.59 0.00 –0.001 0.00 -- - -- - –0.04 0.00 ATS/FFS 0.15 0.01 1.01 0.00 –0.00001 0.00 -- - -- - –0.0003 0.00 % Follower 0.85 7.45 -- - 0.05 0.00 19.16 0.00 0.09 0.03 -- - Follower Flow 0.92 31.45 –156.23 0.00 0.33 0.00 218 0.00 -- - 0.26 0.001 Follower Density 0.92 0.54 –2.72 0.00 0.006 0.00 3.7 0.00 -- - 0.006 0.00 % Impeded 0.7 6.75 -- - 0.03 0.00 8.2 0.004 0.11 0.002 0.11 0.00 Impeded Flow 0.88 23.93 –94.48 0.00 0.19 0.00 119.9 0.00 -- - 0.46 0.00 Impeded Density 0.87 0.42 –1.65 0.00 0.003 0.00 2.04 0.00 -- - 0.009 0.00 -Values in bold are inconsistent with the hypothesized logical relationship. Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 3-NC ATS 0.14 1.56 61.55 0.00 –0.003 0.00 –1.4 0.01 -- - -- - ATS/FFS 0.18 0.01 1.006 0.00 –0.00002 0.00 –0.01 0.03 -- - –0.0002 0.00 % Follower 0.67 12.49 6.71 0.01 0.07 0.00 26 0.00 –0.27 0.00 –0.13 0.00 Follower Flow 0.87 43.6 –294.25 0.00 0.45 0.00 373.3 0.00 -- - -- - Follower Density 0.77 0.87 –4.35 0.00 0.008 0.00 6.47 0.00 -- - -- - % Impeded 0.46 10.92 -- - 0.04 0.00 14.6 0.00 –0.17 0.007 -- - Impeded Flow 0.76 36 –142 0.00 0.25 0.00 207.8 0.00 -- - 0.21 0.04 Impeded Density 0.75 0.65 –2.49 0.00 0.004 0.00 3.62 0.00 -- - 0.004 0.02 -Values in bold are inconsistent with the hypothesized logical relationship. Read the entire page →
From page 171... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 171 Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 4-NC ATS 0.34 1.79 61.36 0.00 –0.004 0.00 –4.99 0.00 -- - –0.02 0.00 ATS/FFS 0.44 0.01 1.02 0.00 –0.00003 0.00 –0.02 0.00 -- - –0.0004 0.00 % Follower 0.84 7.15 –8.98 0.00 0.05 0.00 25.14 0.00 -- - -- - Follower Flow 0.87 39.96 –193.06 0.00 0.32 0.00 255.8 0.00 -- - 0.27 0.002 Follower Density 0.85 0.78 –3.74 0.00 0.006 0.00 4.87 0.00 -- - 0.007 0.00 % Impeded 0.73 6.73 –7.41 0.00 0.04 0.00 15.95 0.00 –0.12 0.001 0.09 0.00 Impeded Flow 0.80 33.56 –133.62 0.00 0.21 0.00 166.3 0.00 –0.35 0.05 0.46 0.00 Impeded Density 0.79 0.65 –2.59 0.00 0.004 0.00 3.18 0.00 -- - 0.009 0.00 -Values in bold are inconsistent with the hypothesized logical relationship. Read the entire page →
From page 172... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 172 B.6.2. Site Specific Regression Results (Class II) Read the entire page →
From page 173... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 173 B.6.3. Site Specific Regression Results (Class III) Read the entire page →
From page 174... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 174 Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 7 - NC ATS 0.19 2.17 62.2 0.00 –0.002 0.00 –2 0.05 –0.02 0.03 –0.05 0.00 ATS/FFS 0.12 0.01 1.007 0.00 –0.000007 0.00 -- - -- - –0.0002 0.00 % Follower 0.85 7.45 –6.74 0.00 0.05 0.00 29.92 0.00 -- - –0.05 0.002 Follower Flow 0.90 30.56 –128.46 0.00 0.28 0.00 203.8 0.00 -- - -- - Follower Density 0.89 0.55 –2.3 0.00 0.005 0.00 3.53 0.00 -- - -- - % Impeded 0.69 6.74 –7.46 0.00 0.03 0.00 23.64 0.00 -- - -- - Impeded Flow 0.83 23.99 –81.4 0.00 0.16 0.00 129 0.00 -- - -- - Impeded Density 0.83 0.42 –1.46 0.00 0.003 0.00 2.24 0.00 -- - 0.002 0.01 -Values in bold are inconsistent with the hypothesized logical relationship. Read the entire page →
From page 175... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 175 C Identification of Viable Simulation Tools for the Analysis of Two-Lane Highways C.1. Read the entire page →
From page 176... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 176 • Ability to model two-lane highways, including passing in the oncoming lane and passing lanes. For those tools that had this ability, considerations included: o Flexibility in adjusting parameters for the applicable models, particularly for passing in a passing lane or the oncoming lane o Can slower or faster vehicles be specified to move into added lane of a passing lane section • Flexibility in modifying parameters affecting vehicle performance • Ability to include multiple point detectors along each link within the network • Robust performance measure output options • Level of documentation of modeling algorithms • Software tool is, or can be made, publicly available • Modern software architecture so that software tool will be able to run on a modern computer operating system for the foreseeable future • Technical support provided by the software developer C.3.1. Read the entire page →
From page 177... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 177 technical merit of the modeling algorithms, level of documentation of the modeling algorithms, software architecture, ease of use, and cost of the tool. We would appreciate it if you would respond to this message and answer the following questions: • Does your software tool have the capability to model any of the following two-lane highway operational features (please check all that apply) Read the entire page →
From page 178... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 178 o What is the cost of your tool (in US$) -- including the initial purchase price and any recurring license/maintenance fees? Read the entire page →
From page 179... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 179 greater realism for vehicle movement modeling than other simulation tools, particularly for commercial vehicles. Differences between SwashSim and CORSIM 6 include: • A 0.1-second simulation time resolution instead of 1 second for CORSIM 6. Read the entire page →
From page 180... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 180 Figure C-2. SwashSim network data entry screen Figure C-3. Read the entire page →
From page 181... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 181 can model and visualize the behavior of complex traffic systems in a 2-dimensional or 3dimensional GIS environment to illustrate and evaluate traffic flow dynamics, traffic signal and ITS operations, and overall network performance. TransModeler…integrates with TransCAD,…[a] Read the entire page →
From page 182... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 182 Figure C-5. TransModeler network coding screen (1) Read the entire page →
From page 183... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 183 D Modeling Speeds of Heavy Vehicles for Simulation Microscopic traffic simulation tools are frequently used to model traffic operations and assess traffic performance. Read the entire page →
From page 184... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 184 ft (100 to 200 m) before the curve, the radius of the curve, length of the approach tangent, grade of the approach tangent, and interaction between the length of the approach tangent and radius of the curve were all found to be significant predictors of the 85th percentile heavy vehicle speed. Read the entire page →
From page 185... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 185 Eck et al. Read the entire page →
From page 186... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 186 tangent, and length of the departure tangent were significant predictors of the 85th percentile curve speed at locations between the point of curvature (PC) and point of tangency (PT) Read the entire page →
From page 187... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 187 sight distances, they concluded that a decrease in the available sight distance increased the mean speed reduction. They also concluded that the traffic volume had a small effect on the mean speed reduction, but not enough to be meaningful. Read the entire page →
From page 188... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 188 and Collins (2000) used the curve speed equations developed by Fitzpatrick et al. Read the entire page →
From page 189... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 189 An R2 value was not reported for this model. Figueroa and Tarko (2007) Read the entire page →
From page 190... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 190 Table D-1. Desired Speed Proportions for Heavy Vehicles Heavy Vehicle Type Desired Speed Proportion Single-Unit Truck 0.98 Intermediate Semi-Trailer Truck 0.95 Interstate Semi-Trailer Truck 0.95 Double Semi-Trailer Truck 0.93 Upgrades Heavy vehicle speeds on upgrades were simulated using a full vehicle dynamics modeling approach. Read the entire page →
From page 191... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 191 multiple major components of the vehicle, including drivetrain components (e.g., engine and transmission) and suspension components, among others. Read the entire page →
From page 192... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 192 Figure D-1. Upgrade speed versus distance curves for a single-unit truck Figure D-2. Read the entire page →
From page 193... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 193 Figure D-3. Upgrade speed versus distance curves for an interstate semi-trailer truck After the speed versus distance curves were developed, a polynomial function was fit to the curves, excluding the constant crawl speed portion. Read the entire page →
From page 194... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 194 Table D-2. Upgrade Speed Model Coefficients for a Single-Unit Truck. Read the entire page →
From page 195... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 195 Table D-4. Upgrade Speed Model Coefficients for an Interstate Semi-Trailer Truck. Read the entire page →
From page 196... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 196 assuming an initial speed of 75 mi/h. These functions can be modified to produce upgrade speeds for different initial speeds. Read the entire page →
From page 197... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 197 1. Determine which upgrade speed function to use: Round the slope of the downgrade (in percent) Read the entire page →
From page 198... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 198 Table D-5. Additional Segment Lengths for Different Initial Speeds for a Single-Unit Truck. Read the entire page →
From page 199... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 199 Table D-7. Additional Segment Lengths for Different Initial Speeds for an Interstate SemiTrailer Truck. Read the entire page →
From page 200... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 200 Table D-9. Crawl Speeds and Corresponding Segment Lengths for an Intermediate SemiTrailer Truck. Read the entire page →
From page 201... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 201 D.4.2. Speeds on Curves Horizontal Curves Comparison of curve speed models. Read the entire page →
From page 202... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 202 Figure D-5. 85th percentile curve speeds of heavy vehicles entering from a tangent with an 85th percentile speed equal to 70 mi/h Figure D-6. Read the entire page →
From page 203... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 203 Figure D-7. 85th percentile curve speeds of heavy vehicles entering from a tangent with an 85th percentile speed equal to 50 mi/h As seen in these figures, the shape of the speed-radii curves for all of the models, except Donnell et al.'s (2001) Read the entire page →
From page 204... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 204 at speeds higher than the curve advisory speed (Bonneson et al., 2007; Chowdhury et al., 1991; Ritchie, 1972) Read the entire page →
From page 205... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 205 percentile tangent speed was assumed to be 11 percent larger than the average tangent speed. This was also based on findings in Bonneson et al.'s (2007) Read the entire page →
From page 206... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 206 speeds on vertical curves. Instead, modeling drivers' desire to travel above the posted speed and accounting for the impact of grade on heavy vehicle speeds was viewed as adequate for modeling vehicle speeds in the vicinity of a vertical curve. Read the entire page →
From page 207... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 207 D.5. Simulation Experimental Design This section describes the range of variables used to develop the proposed methodology. Read the entire page →
From page 208... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 208 (A) Read the entire page →
From page 209... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 209 D.5.2. Simulation Duration and Replications The simulation duration and number of replications can have a significant effect on the simulation results. Read the entire page →
From page 210... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 210 (A) Read the entire page →
From page 211... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 211 (A) Read the entire page →
From page 212... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 212 (A) Read the entire page →
From page 213... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 213 D.5.3. Effect of Opposing Heavy Vehicle Percentage on Passing Zone Segments Opportunities for passing in the opposing lane are largely dictated by the opposing traffic. Read the entire page →
From page 214... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 214 (A) Read the entire page →
From page 215... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 215 (A) Read the entire page →
From page 216... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 216 (A) Read the entire page →
From page 217... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 217 D.5.4. Maximum Analysis Flow Rates on Passing Lane Segments Passing lane segments can significantly improve traffic flow, especially on steep and long grades. Read the entire page →
From page 218... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 218 The trends deduced from Table D-12 are largely attributable to the merging of heavy vehicles at the end of the passing lane. As the heavy vehicle percentage increases, a larger number of heavy vehicles must merge. Read the entire page →
From page 219... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 219 Figure D-18 presents the results for vertical class 1, passing constrained segments with a length of 0.50 mi. This figure shows that there is a slight difference in the ATS for upgrades and downgrades when the heavy vehicle percentage and flow rate are both large. Read the entire page →
From page 220... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 220 (A) Read the entire page →
From page 221... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 221 (A) Read the entire page →
From page 222... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 222 (A) Read the entire page →
From page 223... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 223 (A) Read the entire page →
From page 224... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 224 (A) Read the entire page →
From page 225... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 225 (A) Read the entire page →
From page 226... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 226 (A) Read the entire page →
From page 227... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 227 (A) Read the entire page →
From page 228... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 228 (A) Read the entire page →
From page 229... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 229 (A) Read the entire page →
From page 230... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 230 (A) Read the entire page →
From page 231... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 231 (A) Read the entire page →
From page 232... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 232 (A) Read the entire page →
From page 233... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 233 (A) Read the entire page →
From page 234... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 234 (A) Read the entire page →
From page 235... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 235 D.5.6. Final Set of Parameters for Experimental Design The final set of variables and corresponding ranges of values for the experimental design are presented in Table D-13. Read the entire page →
From page 236... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 236 Table D-14. Directional Flow Rate Values for Varying Heavy Vehicle Percentages and Vertical Alignment Classifications (Passing Lane Segments) Read the entire page →
From page 237... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 237 E Approach for Estimating Follower Status E.1. Read the entire page →
From page 238... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 238 Figure E-1. Theoretical representation of following probability based on headway and speed Source: Catbagan and Nakamura (2010) Read the entire page →
From page 239... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 239 Figure E-2. Follower probability curve A second-order polynomial fit to these data yields the following function: (ℎ ) Read the entire page →
From page 240... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 240 Figure E-3. Survival function and cumulative distribution function plots This survival function can be used directly for estimating following probabilities. Read the entire page →
From page 241... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 241 Step 4 Develop percent followers versus flow rate (for given roadway, traffic, and control factors) relationship; for example, as shown in the following figure. Read the entire page →
From page 242... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 242 Figure E-5. Follower density-flow rate relationship E.1.2. Read the entire page →
From page 243... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 243 value of 3 seconds was used in this study (same as PF) Read the entire page →
From page 244... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 244 reveal some of the patterns and trends that underlie those relationships. Then correlation and regression analyses were conducted to assess the level of association between performance measures and traffic variables. Read the entire page →
From page 245... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 245 Figure E-7. Correlation results of performance measures vs traffic variables Table E-2 shows the results of regression analysis for the study site using a 95% confidence level. Read the entire page →
From page 246... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 246 Table E-2. Results from Multivariate Linear Regression Analysis Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance ATR 47 ATS 0.54 1.22 57.07 0.00 -0.004 0.00 -- -- 0.04 0.00 -0.03 0.00 ATS/FFS 0.04 0.01 1.01 0.00 -- -- -0.03 0.05 -- -- -- -- % Follower 0.68 6.75 -- -- 0.04 0.00 11.46 0.05 -- -- -0.07 0.00 % Followers-Nak 0.74 8.9 -- - 0.06 0.00 20.37 0.008 -- -- -- -- Follower Flow 0.86 15.95 -51.07 0.00 0.17 0.00 72.8 0.00 -- -- -0.11 0.01 Follower Density 0.86 0.3 -0.98 0.00 0.003 0.00 1.36 0.00 -- -- -0.002 0.04 % Impeded 0.56 5.68 -- -- 0.03 0.00 -- -- -- -- -0.04 0.01 Impeded Flow 0.79 13.55 -37.22 0.00 0.12 0.00 51.3 0.00 -- -- -- -- Impeded Density 0.79 0.26 -0.66 0.00 0.002 0.00 0.96 0.00 -- -- -- -- - Values in bold are inconsistent with the hypothesized logical relationship. Read the entire page →
From page 247... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 247 E.2. Following Status on Two-Lane Highways This study aimed to achieve a better understanding of the car-following interaction between vehicles on two-lane two-way highways. Read the entire page →
From page 248... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 248 less than hagg can generally be described as being in following state while those with headways greater than hcon can be described as being independent or in free-flow state. Typical values for the critical headway are expected to be in this range; i.e., between the boundary values hagg and hcon. Read the entire page →
From page 249... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 249 developing a procedure for determining the headway cut-off value used in estimating percent followers; that is, identifying the percentage of vehicles in car-following mode. The proposed procedure is based on the car-following process described earlier and the assumption that the percent followers are directly proportional to the reduction in average speed from that of freeflowing vehicles. Read the entire page →
From page 250... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 250 E.2.4. Headway Speed Investigation As car-following interaction between successive vehicles on the same lane is usually reflected in speed adjustments, speed data were used in examining the car-following parameters on two-lane highways, particularly the critical headway range and boundary values. Read the entire page →
From page 251... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 251 Figure E-9. Headway speed relationship at selected study sites Read the entire page →
From page 252... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 252 Figure E-10. Average speed for headways equal or greater than h at selected study sites E.2.5. Read the entire page →
From page 253... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 253 Figure E-11. Weibull distributions of speed vs headway at selected study sites Table E-4. Read the entire page →
From page 254... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 254 speed" in this analysis. For headways less than two seconds, the percentage of headways with relative speed of ±1 mi/h is more than 40%, which is relatively high given that each headway is associated with two vehicles in the traffic stream and therefore the percentage of "same speed" vehicles is expected to be higher than that of "same speed" headways (generally a function of platoon size) Read the entire page →
From page 255... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 255 The approach followed in this research is based on the premise that average speed and car following status are directly related. It was shown in the previous section that almost all vehicles with headways less than hagg are in car following mode and almost all vehicles with headways greater than hcon are in free-flow mode. Read the entire page →
From page 256... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 256 Assuming average speed in the transition range is directly proportional to percent followers, the frequencies of followers in this range can be determined, and calculations for ATR 32 are summarized in Table E-5. Table E-5. Read the entire page →
From page 257... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 257 The approach described above was applied to all fifteen study sites and the results are summarized in Table E-6. For class I highways, the estimated headway cut-off for percent followers varied between 1.8 and 2.8 seconds with the exception of ATR 92 where the cut-off value is much higher (3.845 seconds) Read the entire page →
From page 258... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 258 E.2.7. Summary of Findings This study presents an empirical investigation into the car-following interaction and the estimation of percent followers on rural two-lane highways. Read the entire page →
From page 259... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 259 F Analysis Methodology Model Development F.1. Read the entire page →
From page 260... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 260 The scatterplots also showed that passing designation influenced the FFS-heavy vehicle percentage relationship. Figure F-1 shows that heavy vehicles exerted a stronger influence on FFS for a passing constrained segment (Figure F-1A) Read the entire page →
From page 261... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 261 (A) Read the entire page →
From page 262... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 262 (A) Read the entire page →
From page 263... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 263 F.1.2. Free-Flow Speed Model Development Linear regression was used to fit a FFS model to the simulation data. Read the entire page →
From page 264... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 264 confidence level, and the adjusted R2 values ranged from 0.988 for vertical class 5 to 0.999 for vertical class 1. The coefficients for vertical class 1 are listed as "N/A" because the slope coefficient is constant for this vertical class. Read the entire page →
From page 265... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 265 Table F-1. Coefficients for FFS-HV% Slope Model (Used in Equation (F-2) Read the entire page →
From page 266... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 266 Table F-1 and Figure (F-5) also show that the BFFS exerted a stronger influence on the slope coefficient for higher vertical alignment classifications and larger opposing rates. Read the entire page →
From page 267... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 267 (A) Read the entire page →
From page 268... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 268 F.2. Models for Estimation of Average Speed Speed-flow relationships obtained from the final set of simulation data were evaluated to ensure the model form presented in Equation (2-6) Read the entire page →
From page 269... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 269 (A) Read the entire page →
From page 270... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 270 Figure F-9 shows that Equation (F-3) produced a better fit to the data than Equation (2-6) Read the entire page →
From page 271... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 271 where m = speed-flow slope coefficient (decimal) FFS = free-flow speed in the analysis direction (mi/h) Read the entire page →
From page 272... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 272 F-10A) than the vertical class 5 model (Figure F-10E) Read the entire page →
From page 273... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 273 Table F-2. Coefficients Used in Speed-Flow Slope Model (Equation (F-4) Read the entire page →
From page 274... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 274 Table F-4. Coefficients Used to Calculate b3 (Equation (F-5) Read the entire page →
From page 275... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 275 Table F-7. Coefficients Used to Calculate b4 (Equation (F-6) Read the entire page →
From page 276... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 276 (A) Read the entire page →
From page 277... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 277 (A) Read the entire page →
From page 278... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 278 (A) Read the entire page →
From page 279... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 279 (A) Read the entire page →
From page 280... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 280 (A) Read the entire page →
From page 281... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 281 (A) Read the entire page →
From page 282... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 282 (A) Read the entire page →
From page 283... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 283 Horizontal Curves For horizontal curves, the slope coefficient is estimated with Equation (F-7) Read the entire page →
From page 284... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 284 function of the vertical alignment classification and segment type, since the coefficients in these equations differ by vertical class and segment type. Table F-8 and Table F-9 present the coefficients for the passing zone/passing constrained segment models. Read the entire page →
From page 285... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 285 F.3. Models for Estimation of Percent Followers The model development process for the estimation of percent followers largely followed that for the average speed models. Read the entire page →
From page 286... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 286 where: b1–b7 = coefficient values, given in Table F-11, and Other terms as defined previously. Table F-11. Read the entire page →
From page 287... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 287 Table F-13. Coefficient Values for Equation (F-13) Read the entire page →
From page 288... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 288 F.4. Passing Lanes Passing is an important operational phenomenon on two-lane, two-way, highways. Read the entire page →
From page 289... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 289 Al-Kaisy and Freedman (2010) Read the entire page →
From page 290... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 290 In a study by Al-Kaisy and Freedman (2010) , the operational improvements downstream of passing lanes were investigated. Read the entire page →
From page 291... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 291 from a study by Al-Kaisy et al (2017) Read the entire page →
From page 292... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 292 miles, 3 miles, 4.7 miles and 7 miles beyond the end of the passing lane. There is another passing lane 4.9 miles after the taper end of the first passing lane. Read the entire page →
From page 293... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 293 Figure F-23. Performance measures along study sites For the calibration of the simulation tool, several outputs from the SwashSim were compared to the field data counterparts. Read the entire page →
From page 294... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 294 this table for comparison purposes. Overall, the average discrepancy for other performance measures is as favorable if not better than that of PF. Read the entire page →
From page 295... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 295 Table F-18. Traffic Simulation Output and Deviations from Field Measurements (Calibration) Read the entire page →
From page 296... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 296 Table F-19. Traffic Simulation Output and Deviations from Field Measurements (Validation) Read the entire page →
From page 297... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 297 For a %NP of 0, passing is allowed along the entire length of the facility, while for a %NP of 100, passing is not allowed in any part. For a %NP of 20, passing is allowed in 4 out of 5 consecutive segments, and so on. Read the entire page →
From page 298... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 298 study to determine the start of the flat portion of the curve; that is, the end of the passing lane effective length: • the percentage difference in FD between successive detector locations was found, • a 5-point moving average (average of the point of interest, two points upstream and two points downstream) of the percentage difference was used to dampen the fluctuations due to randomness in the simulation process (see Figure F-25) Read the entire page →
From page 299... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 299 Table F-20. Effective Length of Passing Lane Using Empirical Method (miles) Read the entire page →
From page 300... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 300 Where the effective length of passing lane is measured in miles, flow rate is measured in veh/h in the direction of analysis and %NP represents the percent-no passing on the two-lane highway for several miles upstream of the passing lane segment in the direction of analysis. As shown in Table F-20, using this cut-off value, the effective length would vary between 19.8 miles for flow rate of 200 veh/h and 0% no-passing and 5.8 miles for a flow rate of 800 veh/h and 100% no-passing zones. Read the entire page →
From page 301... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 301 DownstreamDistance = distance downstream from the start of the passing lane segment (mi) , %Followers = For the effective length calculation and downstream segment %Improve%Followers and %ImproveAvgSpeed calculations: % followers entering the passing lane segment (i.e., % followers estimated at the end of the segment just upstream of the passing lane segment; For the calculation of adjusted follower density downstream of the passing lane: % followers for the analysis segment, PassLaneLength = length of passing lane segment (mi) Read the entire page →
From page 302... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 302 performance measures within the passing lane, but leads to a faster rate of return to platooning downstream of the passing lane. Read the entire page →
From page 303... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 303 Wooldridge et al. Read the entire page →
From page 304... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 304 The two major analysis variables are traffic level and passing lane length. Other variables were held constant at their default values. Read the entire page →
From page 305... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 305 Station 1: 100' Upstream Station 2: 100' Downstream Station 3: 0.5 mi Downstream Figure F-26. Data collection setup, OR 2 and OR 17. Read the entire page →
From page 306... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 306 Satellite imagery data and GIS data were used to code the roadway network in SwashSim. Flow rates between 150-200, and 200-250 veh/h were used in calibrating the software. Read the entire page →
From page 307... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 307 Table F-24. Traffic Simulation Output and Deviations from Field Measurements (Calibration) Read the entire page →
From page 308... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 308 Table F-25. Traffic Simulation Output and Deviations from Field Measurements (Validation) Read the entire page →
From page 309... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 309 detectors were installed at 0.5, 0.75 and 1.25 miles downstream of the passing lane. The average outputs from these three detectors was used to estimate performance downstream of passing lane. Read the entire page →
From page 310... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 310 Figure F-27. Percent reduction in PF to length of passing lane (Harwood approach) Read the entire page →
From page 311... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 311 Proposed New Approach Due to the inconsistent results found using the maximum rate approach described in the previous section, a new approach was proposed and attempted in this investigation. In this approach, the optimum length of a passing lane is derived using the rate of change in performance as passing lane length is increased gradually using small fixed increments. Read the entire page →
From page 312... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 312 To identify the point at which the rate of performance improvement becomes constant (start of linear segment) , the best fit linear relationship was found while varying the length of the linear portion of the curve and the length with the best fit (highest R2) Read the entire page →
From page 313... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 313 the proposed approach correspond closely to the lengths provided by 22.5% and 25% reductions in PF. This finding is further illustrated in Figure F-30. Read the entire page →
From page 314... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 314 A linear regression model for percent reduction in PF was developed using traffic flow and passing lane length as explanatory variables as shown in the following equation: Percent Reduction in PF = 0.21 − 0.000218 × FlowRate + 0.09 × PassLaneLength (F-21) Where FlowRate equals traffic flow rate in veh/h and PassLaneLength equals the length of the passing lane, in miles. Read the entire page →
From page 315... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 315 Summary of Findings This task presents an investigation into the optimum length of passing lanes on two-lane-two way highways. The effect of traffic level on the optimum length of passing lanes was examined using a microscopic traffic simulation program called "SwashSim". Read the entire page →
From page 316... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 316 Refer to the truck speed-distance curves in Figure D-1, Figure D-2, and Figure D-3 to determine speed reduction on the grade. Alternatively, Equation (D-2) Read the entire page →
From page 317... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 317 Figure F-31. Schematic of example 2+1 configuration (passing vehicles use center lane) Read the entire page →
From page 318... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 318 F.5.1. Literature Review Europe The following information is summarized from a combination of the report "Application of European 2+1 Roadways Designs" (Potts and Harwood, 2003) Read the entire page →
From page 319... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 319 Figure F-34. Aerial photo of 2+1 site in Germany (Highway B169 south of Berlin) Read the entire page →
From page 320... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 320 • Finland o First 2+1 highway opened in 1991. o Guidelines for the transition lengths (buffer area between opposing passing lanes) Read the entire page →
From page 321... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 321 o 55 mi/h (90 km/h) typical posted speed limit. Read the entire page →
From page 322... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 322 Performance Measures • Germany o Traffic volumes range from 15,000 veh/day to 25,000 veh/day; the maximum traffic volume level observed was 30,000 veh/day. o Capacity: 1350 veh/h/ln (2-lane w/o passing lanes) Read the entire page →
From page 323... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 323 o Travel speeds at low flow rates were 0.6–1.2 mi/h (1–2 km/h) higher for the 2+1 roadway than for the two-lane cross section it replaced. Read the entire page →
From page 324... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 324 Sites in Kansas and Minnesota were used as case studies for collecting vehicle passing and geometry data over a 6-hour study period. The data were collected using cameras and counters and consisted of 15-minute vehicle counts and the following information on each vehicle: speed, headway, number of axles, direction, and time stamp. Read the entire page →
From page 325... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 325 Some of the conclusions reached either through field observation or simulation results include that a large numbers of vehicles began passing maneuvers at the beginning of the section but not all vehicles in the left lane actually used the left lane for passing. For example SH-121 showed 91.9% northbound and 65.9% southbound vehicles in the left lane passing and US-183 showed 24.9% northbound and 80.3% southbound vehicles in the left lane passing. Read the entire page →
From page 326... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 326 F.5.2. Simulation Tool Enhancements The SwashSim simulation tool was modified, such that for passing lane segments, either lane can be designated for use by passing vehicles. Read the entire page →
From page 327... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 327 experimental design. A total of 3 to 7 passing lanes were used in each direction of the evaluation segment depending on the length of passing lane segment. Read the entire page →
From page 328... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 328 Figure F-38. 2+1 network representation in SwashSim animation Station 1: 25 % of section length Station 2: 50 % of section length Station 3: 75 % of section length Station 4: 25 % of section length Station 5: 50 % of section length Station 6: 75 % of section length Transition segment (1000 ft) Read the entire page →
From page 329... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 329 Based on the simulation data obtained from the experimental design, the following models were obtained to estimate the change in performance between a 2+1 configuration and a comparable two-lane highway with no passing lanes, approximately 50% passing zones, and 16-18 miles in length. Read the entire page →
From page 330... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 330 F.6. Level of Service The service measures, and corresponding level of service (LOS) Read the entire page →
From page 331... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 331 • Run the experimental design with the batch processing utility in HCM-CALC (Figure F-40) for the HCM 2010 methodology. Read the entire page →
From page 332... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 332 follower density due to the lower speed. The LOS threshold values derived from this process are shown in Table F-35. Read the entire page →
From page 333... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 333 Follower density, for use with Table F-35 is calculated as follows. Read the entire page →
From page 334... ... Final Report 334 H Field Data Collection Supplemental Material Introduction Two-lane highway field data were an important aspect of the research approach. Read the entire page →
From page 335... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 335 North Carolina Sites Summary Location of Data Sites Read the entire page →
From page 336... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 336 Summary of North Carolina Field Data Collection Site ID Site Location Latitude Longitude Date Range Total Hours Number of Detectors Average Total Number of Vehicles (veh/detector) 1 US-43 34°56'28.16" -77°14'18.71" 06/08/201506/16/2015 186 6 84748 2 US-64 35°58'43.55" -78°35'12.95" 04/20/201504/28/2015 186 4 121753 3 US-17 35°52'10.55" -75°48'3.38" 06/15/201506/23/2015 187 5 39226 4 US-17 35°11'26.51" -77° 7'54.79" 06/09/201506/17/2015 187 5 96420 5 US-54 35°55'18.37" -79° 6'27.76" 05/18/201505/27/2015 187 5 120186 6 US-98 35°58'54.20" -78°44'31.88" 04/20/201504/28/2015 187 4 85417 7 US-17 35°16'46.86" -77° 7'18.13" 06/08/201506/16/2015 187 5 99644 Configuration of data collection equipment Read the entire page →
From page 337... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 337 Site 1: US 17/ NC 58, NC 58 to NC 58 Highway/Segment US 17/ NC 58, NC 58 to NC 58 County Jones Approximate AADT 12000 Truck Percentage SU 4.5%-MU 3.2% Passing Distance Long Passing Direction Both directions Read the entire page →
From page 338... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 338 Site 2: NC 98, Thompson Mill to Stony Hill Highway/Segment NC 98, Thompson Mill to Stony Hill County Wake Approximate AADT 15000 Truck Percentage SU 3.3%-MU 1.3% Passing Distance Short Passing Direction Both directions Read the entire page →
From page 339... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 339 Site 3: US 64, Columbia to US 264 Highway/Segment US 64, Columbia to US 264 County Tyrell, Dare Approximate AADT 3000-4000 High Seasonal Variation Highest daily volume (in summer) is around 10000 Truck Percentage SU 5.3%-MU 4.3% Passing Distance Long Passing Direction Both directions Read the entire page →
From page 340... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 340 Site 4: NC 43, NC 55 to Spring Garden Highway/Segment NC 43, NC 55 to Spring Garden County Craven Approximate AADT 17000 Truck Percentage SU 3.1%-MU 3.5% Passing Distance Short Passing Direction Some both ways Read the entire page →
From page 341... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 341 Site 5: NC 54, Old Fayetteville to Salem Church Highway/Segment NC 54, Old Fayetteville to Salem Church County Orange Approximate AADT 13000 Truck Percentage SU 2.6%-MU 2.2% Passing Distance Short Passing Direction Both directions Read the entire page →
From page 342... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 342 Site 6: NC 98, Old Creedmor to Patterson Highway/Segment NC 98, Old Creedmor to Patterson County Durham, Wake Approximate AADT 12000 Truck Percentage SU 1.9%-MU 1.5% Passing Distance Short Passing Direction Alternating directions Read the entire page →
From page 343... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 343 Site 7: NC 17/NC 43, Macedonia Church to US 17 Business Highway/Segment NC 17/NC 43, Macedonia Church to US 17 Business County Durham, Craven Approximate AADT 10000 High Seasonal Variation Volume on Friday in summer can be up to 35%-40% higher than AADT Truck Percentage SU 4.7%-MU 4.5% Passing Distance Medium Passing Direction Both directions Read the entire page →
From page 344... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 344 Site 8: NC 73, Club to McGuire Highway/Segment NC 73, Club to McGuire County Lincoln, Mecklenburg Approximate AADT 19000 Truck Percentage SU 3%-MU 1.3% Passing Distance Short Passing Direction Both directions Read the entire page →
From page 345... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 345 Oregon Sites Summary The main feature for locations chosen in Oregon is that all sites have passing lanes while there are not many driveways. Data were collected from two passing lane sites and two climbing lane sites (a passing lane on an upgrade section of roadway) Read the entire page →
From page 346... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 346 Site 2 Site 13 Site 11 Read the entire page →
From page 347... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 347 Site 17 Read the entire page →
From page 348... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 348 Detector locations Summary of Oregon Field Data Collection Site ID Site Location Latitude Longitude Date Range Total Hours Number of Detectors Average Total Number of Vehicles (veh/detector) Read the entire page →
From page 349... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 349 Sites with an upgrade section of passing lane (i.e., climbing lane) Count location 13: Sherman Hwy Highway/Segment Sherman Hwy Approximate AADT 2800 Truck AADT 1283 Truck Percentage SU 38.2% Passing Direction Both directions Number of lanes 3 Read the entire page →
From page 350... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 350 Count location 17: Warm Springs Hwy Highway/Segment Warm Springs Hwy Approximate AADT 4300 Truck AADT 1306 Truck Percentage SU 20% Passing Direction Alternative direction Number of lanes 3 Read the entire page →
From page 351... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 351 Sites with a level section of passing lane Count location 11: Mckenzie Hwy Highway/Segment Mckenzie Hwy Approximate AADT 4200 Truck AADT 364 Truck Percentage SU 9% Passing Direction Both directions Number of lanes 3 Read the entire page →
From page 352... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 352 Count location 2: The Dalles-California Hwy Highway/Segment The Dalles-California Hwy Approximate AADT 3700 Truck AADT 1530 Truck Percentage SU 42.7% Passing Direction Both directions Number of lanes 4 Read the entire page →
From page 353... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 353 Montana, Idaho Sites Summary ATR 28 ATR 43 ATR 73 ATR 132 Montana data collection sites Read the entire page →
From page 354... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 354 ATR 47 ATR 147 ATR 44 ATR 126 Idaho data collection sites Read the entire page →
From page 355... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 355 MSU: US 287 A MSU: US 191 MSU: US 287B Data collection setups at sample of Montana sites Read the entire page →
From page 356... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 356 Description of Field Data at Study Sites Site name Dates Class Duration of data collection (hours) Total vehicle count (veh) Read the entire page →
From page 357... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 357 California Site Summary A site was chosen for data collection SR-37 (Sears Point Rd) , north of San Francisco, because of its regular high traffic demands. Read the entire page →
From page 358... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 358 California, SR-37, data collection site Source: Google Earth Read the entire page →
From page 359... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 359 Data Processing The amount of field data collected in the project was voluminous. The Oregon and North Carolina sites each used multiple detectors, with each detector recording event-level data (i.e., data for each passing vehicle) Read the entire page →
From page 360... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 360 Screen which displays values and statistics for a large number of measures, in tabular form. Screen which displays values for a large number of measures, in graphical form: Histogram of all vehicle speeds Read the entire page →
From page 361... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 361 Histogram of speeds for two truck classes. Histogram of vehicle headways Read the entire page →
From page 362... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 362 Histogram of platoon lengths Speed versus flow rate graph Read the entire page →
From page 363... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 363 Speed versus flow rate graph ("zoomed in" flow rate axis) Read the entire page →
From page 364... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 364 Detector Data for North Carolina and Oregon Sites Read the entire page →
From page 365... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 365 Site 11: Speed-Flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: * Read the entire page →
From page 366... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 366 Site 11: Speed-Flow Relationship in Westbound (No passing lane) (East to the right) Read the entire page →
From page 367... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 367 Site 11: Percent follower-Flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: * Read the entire page →
From page 368... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 368 Site 11: Percent follower-Flow Relationship in Westbound (No passing lane) (East to the right) Read the entire page →
From page 369... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 369 Site 11: Percent follower–opposing flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: * Read the entire page →
From page 370... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 370 Site 11: Percent follower-opposing flow Relationship in Westbound (No passing lane) (East to the right) Read the entire page →
From page 371... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 371 Site 11: Follower density-Flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: * Read the entire page →
From page 372... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 372 Site 11: Follower density-Flow Relationship in Westbound (No passing lane) (East to the right) Read the entire page →
From page 373... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 373 Site 11: Follower density-opposing flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: * Read the entire page →
From page 374... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 374 Site 11: Follower density-opposing flow Relationship in Westbound (No passing lane) (East to the right) Read the entire page →
From page 375... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 375 Site 11: Percent impeded-Flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: * Read the entire page →
From page 376... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 376 Site 11: Percent impeded -Flow Relationship in Westbound (No passing lane) (East to the right) Read the entire page →
From page 377... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 377 Site 11: Percent impeded-opposing flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: * Read the entire page →
From page 378... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 378 Site 11: Percent impeded-opposing flow Relationship in Westbound (No passing lane) (East to the right) Read the entire page →
From page 379... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 379 Site 11: Impeded density-Flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: * Read the entire page →
From page 380... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 380 Site 11: Impeded density-Flow Relationship in Westbound (No passing lane) (East to the right) Read the entire page →
From page 381... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 381 Site 11: Impeded density-opposing flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: * Read the entire page →
From page 382... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 382 Site 11: Impeded density -opposing flow Relationship in Westbound (No passing lane) (East to the right) Read the entire page →
From page 383... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 383 Site 11: Headway distribution in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: * Read the entire page →
From page 384... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 384 Site 11: Headway distribution in Westbound (No passing lane) (East to the right) Read the entire page →
From page 385... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 385 Site 11: Speed distribution in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: * Read the entire page →
From page 386... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 386 Site 11: Speed distribution in Westbound (No passing lane) (East to the right) Read the entire page →
From page 387... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 387 Site 13: Speed-flow Relationship in Southbound (5-min aggregation) (North to the left) Read the entire page →
From page 388... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 388 Site 13: Speed-flow Relationship in Northbound (No passing lane) (5-min aggregation) Read the entire page →
From page 389... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 389 Site 13: Percent follower-flow Relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 390... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 390 Site 13: Percent follower-flow Relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 391... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 391 Site 13: Percent follower-opposing flow Relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 392... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 392 Site 13: Percent follower-opposing flow Relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 393... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 393 Site 13: Follower density-flow Relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 394... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 394 Site 13: Follower density-flow Relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 395... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 395 Site 13: Follower density-opposing flow Relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 396... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 396 Site 13: Follower density-opposing flow Relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 397... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 397 Site 13: Percent impeded- flow Relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 398... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 398 Site 13: Percent impeded-flow Relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 399... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 399 Site 13: Percent impeded-opposing flow Relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 400... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 400 Site 13: Percent impeded-opposing flow Relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 401... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 401 Site 13: Impeded density-flow Relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 402... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 402 Site 13: Impeded density-flow Relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 403... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 403 Site 13: Impeded density-opposing flow Relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 404... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 404 Site 13: Impeded density-opposing flow Relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 405... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 405 Site 13: Headway distribution in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 406... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 406 Site 13: Headway distribution in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 407... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 407 Site 13: Speed distribution in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 408... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 408 Site 13: Speed distribution in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 409... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 409 Site 17: Speed-flow relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 410... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 410 Site 17: Speed-flow relationship in Southbound (15-min aggregation) (Continued) Read the entire page →
From page 411... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 411 Site 17: Speed-flow relationship in Northbound (15-min aggregation) (North to the left) Read the entire page →
From page 412... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 412 Site 17: Speed-flow relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 413... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 413 Site 17: Percent follower-flow relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 414... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 414 Site 17: Percent follower-flow relationship in Southbound (No passing lane) (15-min aggregation) Read the entire page →
From page 415... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 415 Site 17: Percent follower -flow relationship in Northbound (15-min aggregation) (North to the left) Read the entire page →
From page 416... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 416 Site 17: Percent follower -flow relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 417... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 417 Site 17: Percent follower-opposing flow relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 418... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 418 Site 17: Percent follower-opposing flow relationship in Southbound (No passing lane) (15-min aggregation) Read the entire page →
From page 419... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 419 Site 17: Percent follower–opposing flow relationship in Northbound (15-min aggregation) (North to the left) Read the entire page →
From page 420... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 420 Site 17: Percent follower–opposing flow relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 421... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 421 Site 17: Follower density-flow relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 422... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 422 Site 17: Follower density-flow relationship in Southbound (15-min aggregation) (Continued) Read the entire page →
From page 423... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 423 Site 17: Follower density-flow relationship in Northbound (15-min aggregation) (North to the left) Read the entire page →
From page 424... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 424 Site 17: Follower density-flow relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 425... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 425 Site 17: Follower density-opposing flow relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 426... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 426 Site 17: Follower density-opposing flow relationship in Southbound (No passing lane) (15-min aggregation) Read the entire page →
From page 427... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 427 Site 17: Follower density–opposing flow relationship in Northbound (15-min aggregation) (North to the left) Read the entire page →
From page 428... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 428 Site 17: Follower density –opposing flow relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 429... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 429 Site 17: Percent impeded -flow relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 430... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 430 Site 17: Percent impeded -flow relationship in Southbound (No passing lane) (15-min aggregation) Read the entire page →
From page 431... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 431 Site 17: Percent impeded -flow relationship in Northbound (15-min aggregation) (North to the left) Read the entire page →
From page 432... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 432 Site 17: Percent impeded-flow relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 433... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 433 Site 17: Percent impeded-opposing flow relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 434... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 434 Site 17: Percent impeded-opposing flow relationship in Southbound (No passing lane) (15-min aggregation) Read the entire page →
From page 435... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 435 Site 17: Percent impeded –opposing flow relationship in Northbound (15-min aggregation) (North to the left) Read the entire page →
From page 436... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 436 Site 17: Percent impeded–opposing flow relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 437... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 437 Site 17: Impeded density-flow relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 438... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 438 Site 17: Impeded density -flow relationship in Southbound (No passing lane) (15-min aggregation) Read the entire page →
From page 439... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 439 Site 17: Impeded density -flow relationship in Northbound (15-min aggregation) (North to the left) Read the entire page →
From page 440... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 440 Site 17: Impeded density-flow relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 441... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 441 Site 17: Impeded density -opposing flow relationship in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 442... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 442 Site 17: Impeded density -opposing flow relationship in Southbound (No passing lane) (15-min aggregation) Read the entire page →
From page 443... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 443 Site 17: Impeded density –opposing flow relationship in Northbound (15-min aggregation) (North to the left) Read the entire page →
From page 444... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 444 Site 17: Impeded density –opposing flow relationship in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 445... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 445 Site 17: Headway distribution in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 446... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 446 Site 17: Headway distribution in Southbound (No passing lane) (15-min aggregation) Read the entire page →
From page 447... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 447 Site 17: Headway distribution in Northbound (15-min aggregation) (North to the left) Read the entire page →
From page 448... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 448 Site 17: Headway distribution in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 449... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 449 Site 17: Speed distribution in Southbound (15-min aggregation) (North to the left) Read the entire page →
From page 450... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 450 Site 17: Speed distribution in Southbound (No passing lane) (15-min aggregation) Read the entire page →
From page 451... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 451 Site 17: Speed distribution in Northbound (15-min aggregation) (North to the left) Read the entire page →
From page 452... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 452 Site 17: Speed distribution in Northbound (No passing lane) (15-min aggregation) Read the entire page →
From page 453... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 453 North Carolina Sites Data Summary Read the entire page →
From page 454... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 454 Summary of North Carolina Field Data Collection Site ID Site Location Latitude Longitude Date Range Total Hours Number of Detectors Average Total Number of Vehicles 1 US-43 34°56'28.16" -77°14'18.71" 06/08/201506/16/2015 186 6 84748 2 US-64 35°58'43.55" -78°35'12.95" 04/20/201504/28/2015 186 4 121753 3 US-17 35°52'10.55" -75°48'3.38" 06/15/201506/23/2015 187 5 39226 4 US-17 35°11'26.51" -77° 7'54.79" 06/09/201506/17/2015 187 5 96420 5 US-54 35°55'18.37" -79° 6'27.76" 05/18/201505/27/2015 187 5 120186 6 US-98 35°58'54.20" -78°44'31.88" 04/20/201504/28/2015 187 4 85417 7 US-17 35°16'46.86" -77° 7'18.13" 06/08/201506/16/2015 187 5 99644 Read the entire page →
From page 455... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 455 Site 4: Speed-flow Relationship (North to the left) (5-min aggregation) Read the entire page →
From page 456... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 456 Site 4: Percent follower-flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 457... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 457 Site 4: Percent follower-opposing flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 458... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 458 Site 4: Follower density-flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 459... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 459 Site 4: Follower density-opposing flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 460... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 460 Site 4: Impeded density-flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 461... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 461 Site 4: Impeded density-opposing flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 462... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 462 Site 4: Percent impeded-flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 463... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 463 Site 4: Percent impeded-opposing flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 464... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 464 Site 4: Headway distribution (North to the left) NB: Detector A Detector B Detector C Detector D Detector E SB: Detector A Detector B Detector C Detector D Detector E Read the entire page →
From page 465... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 465 Site 4: Speed distribution (North to the left) NB: Detector A Detector B Detector C Detector D Detector E SB: Detector A Detector B Detector C Detector D Detector E Read the entire page →
From page 466... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 466 Site 1: Speed-flow Relationship (North to the left) (5-min aggregation) Read the entire page →
From page 467... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 467 Site 1: Percent follower-flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 468... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 468 Site 1: Percent follower-opposing flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 469... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 469 Site 1: Follower density-flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 470... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 470 Site 1: Follower density-opposing flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 471... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 471 Site 1: Impeded density-flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 472... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 472 Site 1: Impeded density-opposing flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 473... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 473 Site 1: Percent impeded-flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 474... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 474 Site 1: Percent impeded-opposing flow Relationship (North to the left) (15-min aggregation) Read the entire page →
From page 475... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 475 Site 1: Headway distribution (North to the left) NB: Detector A Detector B Detector C Detector D Detector E Detector F SB: Detector A Detector B Detector C Detector D Detector E Detector F Read the entire page →
From page 476... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 476 Site 1: Speed distribution (North to the left) NB: Detector A Detector B Detector C Detector D Detector E Detector F SB: Detector A Detector B Detector C Detector D Detector E Detector F Read the entire page →
From page 477... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 477 Site 2: Speed-flow Relationship (East to the right) (5-min aggregation) Read the entire page →
From page 478... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 478 Site 2: Percent follower-flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 479... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 479 Site 2: Percent follower-opposing flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 480... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 480 Site 2: Follower density-flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 481... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 481 Site 2: Follower density-opposing flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 482... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 482 Site 2: Impeded density-flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 483... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 483 Site 2: Impeded density-opposing flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 484... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 484 Site 2: Percent impeded-flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 485... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 485 Site 2: Percent impeded-opposing flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 486... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 486 Site 2: Headway distribution (East to the right) EB: Detector A Detector B Detector C Detector D WB: Detector A Detector B Detector C Detector D Read the entire page →
From page 487... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 487 Site 2: Speed distribution (East to the right) EB: Detector A Detector B Detector C Detector D WB: Detector A Detector B Detector C Detector D Read the entire page →
From page 488... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 488 Site 3: Speed-flow Relationship (East to the left) (5-min aggregation) Read the entire page →
From page 489... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 489 Site 3: Percent follower-flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 490... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 490 Site 3: Percent follower-opposing flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 491... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 491 Site 3: Follower density-flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 492... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 492 Site 3: Follower density-opposing flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 493... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 493 Site 3: Impeded density-flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 494... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 494 Site 3: Impeded density-opposing flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 495... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 495 Site 3: Percent impeded-flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 496... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 496 Site 3: Impeded density-opposing flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 497... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 497 Site 3: Headway distribution (East to the left) EB: Detector A Detector B Detector C Detector D Detector E WB: Detector A Detector B Detector C Detector D Detector E Read the entire page →
From page 498... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 498 Site 3: Speed distribution (East to the left) EB: Detector A Detector B Detector C Detector D Detector E WB: Detector A Detector B Detector C Detector D Detector E Read the entire page →
From page 499... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 499 Site 5: Speed-flow Relationship (East to the left) (5-min aggregation) Read the entire page →
From page 500... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 500 Site 5: Percent follower-flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 501... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 501 Site 5: Percent follower-opposing flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 502... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 502 Site 5: Follower density-flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 503... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 503 Site 5: Follower density-opposing flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 504... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 504 Site 5: Impeded density-flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 505... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 505 Site 5: Impeded density-opposing flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 506... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 506 Site 5: Percent impeded-flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 507... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 507 Site 5: Percent impeded-opposing flow Relationship (East to the left) (15-min aggregation) Read the entire page →
From page 508... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 508 Site 5: Headway distribution (East to the left) EB: Detector A Detector B Detector C Detector D Detector E WB: Detector A Detector B Detector C Detector D Detector E Read the entire page →
From page 509... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 509 Site 5: Speed distribution (East to the left) EB: Detector A Detector B Detector C Detector D Detector E WB: Detector A Detector B Detector C Detector D Detector E Read the entire page →
From page 510... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 510 Site 6: Speed-flow Relationship (East to the right) (5-min aggregation) Read the entire page →
From page 511... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 511 Site 6: Percent follower-flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 512... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 512 Site 6: Percent follower-opposing flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 513... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 513 Site 6: Follower density-flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 514... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 514 Site 6: Follower density-opposing flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 515... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 515 Site 6: Impeded density-flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 516... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 516 Site 6: Impeded density-opposing flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 517... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 517 Site 6: Percent impeded-flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 518... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 518 Site 6: Percent impeded-opposing flow Relationship (East to the right) (15-min aggregation) Read the entire page →
From page 519... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 519 Site 6: Headway distribution (East to the right) EB: Detector A Detector B Detector C Detector D WB: Detector A Detector B Detector C Detector D Read the entire page →
From page 520... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 520 Site 6: Speed distribution (East to the right) EB: Detector A Detector B Detector C Detector D WB: Detector A Detector B Detector C Detector D Read the entire page →
From page 521... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 521 Site 7: Speed-flow Relationship (North to the right) (5-min aggregation) Read the entire page →
From page 522... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 522 Site 7: Percent follower-flow Relationship (North to the right) (15-min aggregation) Read the entire page →
From page 523... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 523 Site 7: Percent follower-opposing flow Relationship (North to the right) (15-min aggregation) Read the entire page →
From page 524... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 524 Site 7: Follower density-flow Relationship (North to the right) (15-min aggregation) Read the entire page →
From page 525... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 525 Site 7: Follower density-opposing flow Relationship (North to the right) (15-min aggregation) Read the entire page →
From page 526... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 526 Site 7: Impeded density-flow Relationship (North to the right) (15-min aggregation) Read the entire page →
From page 527... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 527 Site 7: Impeded density-opposing flow Relationship (North to the right) (15-min aggregation) Read the entire page →
From page 528... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 528 Site 7: Percent impeded-flow Relationship (North to the right) (15-min aggregation) Read the entire page →
From page 529... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 529 Site 7: Percent impeded-opposing flow Relationship (North to the right) (15-min aggregation) Read the entire page →
From page 530... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 530 Site 7: Headway distribution (North to the right) NB: Detector A Detector B Detector C Detector D Detector E SB: Detector A Detector B Detector C Detector D Detector E Read the entire page →
From page 531... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 531 Site 7: Speed distribution (North to the right) NB: Detector A Detector B Detector C Detector D Detector E SB: Detector A Detector B Detector C Detector D Detector E Read the entire page →
From page 532... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 532 I Simulation Tools Supplemental Material Developing a Two-Lane Highway Simulation in SwashSim After you have installed the program, double-click on the SwashSim icon on your desktop or within the ‘Start' menu. Read the entire page →
From page 533... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 533 Figure I-2. Project Selection Dialog Main Input Screen The main input screen (Figure 3) Read the entire page →
From page 534... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 534 Segment Input Fields Links and their corresponding characteristics are specified for the west-to-east or north-to-south travel direction and the inputs for the opposing travel direction are automatically created. Upstream/Downstream Node ID • Each two-lane highway segment has a beginning and ending node. Read the entire page →
From page 535... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 535 Free-Flow Speed Method For tangent links, the free-flow speed must be entered directly. For curved links, the free-flow speed can be entered directly or it can be estimated. Read the entire page →
From page 536... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 536 Detectors Detectors allow one to set points along the segment to measure specific items, such as speed, volume, etc. To set detectors on a segment click on ‘Set' under ‘Set Detector(s) Read the entire page →
From page 537... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 537 Figure I-5. Traffic Data Toolbar Button Figure I-6. Read the entire page →
From page 538... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 538 Saving a Project File To save your project input values to a file, select ‘Save' from the ‘File' menu. The name of the saved file will be displayed in the upper-right corner of the main inputs screen. Read the entire page →
From page 539... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 539 Figure I-8. Simulation Control Panel (Single Run) Read the entire page →
From page 540... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 540 Warm-up Time This field dictates how long the traffic simulation will run before performance measurement data are collected. Enter a number between 1 and 1800 seconds. Read the entire page →
From page 541... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 541 simulation time have been simulated. When the simulation run has completed, the textbox will also show the total computer run time and the number of vehicles that were generated. Read the entire page →
From page 542... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 542 Figure I-12. Animation Screen (2) Read the entire page →
From page 543... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 543 Figure I-13. Vehicle Properties Form Read the entire page →
From page 544... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 544 Developing a Two-Lane Highway Simulation in TransModeler Create a New Simulation  Select "New File" on far left of standard toolbar  Select "With a New Simulation Database"  On Confirm screen select "No" to continue without creating a map  Create file name, save, and begin Creating Segments on TransModeler  Add links (Under ‘Streets' tab in TransModeler Sidebar) • Double-Click to set link • Right click to Un-Do link placement • Press "Esc" button to escape function Read the entire page →
From page 545... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 545 Figure I-14. TransModeler Sidebar  Save Edits after adding links Figure I-15. Read the entire page →
From page 546... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 546 Figure I-16. Defining Links • Under ‘Lane' tab change Lane Changing to Left to Allowed. Read the entire page →
From page 547... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 547  Select the Edit Class box under Link Attributes and the "Edit Road Class" box will open Figure I-18. Edit Road Class  From this box the Speed Limit can be set, which is the main factor for speed within network for simulation  Desired Speed Distribution can also be selected from this window. Read the entire page →
From page 548... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 548 Adding Centroids (Traffic Flow) In the transportation planning context, "centroids" are nodes in a transportation network that represent a geographic area called a traffic analysis zone (TAZ) Read the entire page →
From page 549... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 549 Figure I-21. Centroid Direction  Add centroid to network by selecting the ‘Add Centroid' in TransModeler Sidebar and then selecting the link to place it on. Read the entire page →
From page 550... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 550 Adding Lanes  Lanes can be added under the Streets Tab of the TransModeler Sidebar Figure I-22. Lanes  Select the ‘Add a Lane' button and then select the road in which to add lane  Select ‘Save Edits' once complete Adding Lane Connectors  Lane connectors direct the flow of traffic on lanes and links  Select ‘Add a Lane Connector' under the Streets Tab of the TransModeler Sidebar Figure 22  Select lane in which to place connector, and if it is suitable for the simulation TransModeler will allow the addition of the lane connector Elevation  To edit elevation select the in the Trans Modeler Sidebar Figure I-23. Read the entire page →
From page 551... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 551 Figure I-24. Elevation Creating and Adding Trip Matrix (Traffic Flow) Read the entire page →
From page 552... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 552 Figure I-26. Trip Matrix: Origin & Destinations  Create Matrix name and Save  A "Trip Matrix Settings" box will appear where Setup and Content can be added  Under the "Content" Tab more matrices can be added with specification on vehicle type  Once Setup/Content is complete a blank graph will appear Figure I-27. Read the entire page →
From page 553... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 553 Adding  To add and edit trip matrices select "Project Settings" on the TransModeler sidebar under the Simulation Tab Figure I-29. Project Settings  Under the input tab in "Project Settings" the list of Trip Tables used for the network will be displayed. Read the entire page →
From page 554... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 554 Passing  Located under Simulation > Parameters > Driver Behavior Figure I-31. Passing  Select Passing > Choose General Before a subject vehicle will consider passing in the opposite direction, certain conditions must be met: • The driver must be traveling at a speed a certain threshold, the minimum desired speed deficit, below its desired speed. Read the entire page →
From page 555... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 555 • A distance downstream derived from a minimum time headway and its current speed (i.e., distance = current speed * minimum time headway) Read the entire page →
From page 556... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 556 Designating Passing Lanes  After adding lanes to a segment, passing lanes can be designated  With the ‘Info' button click the lane that should be the passing lane Figure I-32. Info  Within the Edit Road Properties box select the ‘Lanes' tab. Read the entire page →
From page 557... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 557 Figure I-34. Adding Sensors  Select location on network to place sensor and specify properties in the "Edit Sensor Properties" box Figure I-35. Read the entire page →
From page 558... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 558 Figure I-36. Save Edits Outputs  To edit outputs select "Project Settings" under the Simulation tab of the TransModeler Sidebar. Read the entire page →
From page 559... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 559 Figure I-38. Output Tab on TransModeler Sidebar  Select Group and Report type from drop downs to specify what outputs to present  Select ‘Create Report' to create Output Report Figure I-39. Read the entire page →
From page 560... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 560  Under the Output tab of the "Project Settings" box make sure ‘Playback' is selected Figure 37  To access playbacks select "Simulation Settings" under Simulation tab of TransModeler Sidebar Figure I-40. Simulation Settings  In the Simulation Settings box select ‘Playback' and the skip increments (time between frames) Read the entire page →
From page 561... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 561 Figure I-42. Begin Playback Read the entire page →
From page 562... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 562 Simulation Calibration Traffic simulation models are powerful tools that require calibration and validation. Calibration adjusts simulation parameters so the simulation outputs agree well with ground truth conditions. Read the entire page →
From page 563... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 563 somewhat different parameter values across the sites due to varying characteristics across sites. All of these settings were used to guide the selection of proper/reasonable parameter settings for the networks developed to use for the experimental design to generate the performance measure functions/relationships. Read the entire page →
From page 564... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 564 Oregon Site ID Time Interval Total Detectors 11 16:00-17:00 6 13 13:00-14:00 6 17 15:00-16:00 12 North Carolina Site ID Time Interval Total Detectors 1 16:00-17:00 6 4 16:00-17:00 5 7 16:00-17:00 5 Montana Site ID Time Interval Total Detectors 132 11:00-12:00 1 73 10:00-11:00 1 Idaho Site ID Time Interval Total Detectors 47 10:00-11:00 1 44 9:00-10:00 1 The data analysis revealed that the two most prevalent heavy vehicle categories were single-unit trucks and tractor+semi-trailer trucks (commonly referred to as tractor-trailers) Read the entire page →
From page 565... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 565 Oregon Oregon Site 11 Direction WB EB Volume Percentage Volume Percentage Passenger Car 114 64.43% 136 59.35% Pickups 35 19.96% 54 23.38% Single Unit 17 9.84% 28 12.24% Tractor-Trailer 10 5.77% 12 5.03% Oregon Site 13 Direction SB NB Volume Percentage Volume Percentage Passenger Car 63 54.49% 67 59.76% Pickups 14 12.03% 18 16.24% Single Unit 12 10.58% 9 7.9% Tractor-Trailer 26 22.9% 18 16.1% Oregon Site 17 Direction SB NB Volume Percentage Volume Percentage Passenger Car 178 70.25% 190 69.82% Pickups 43 17.04% 45 16.63% Single Unit 20 7.82% 20 7.45% Tractor-Trailer 12 4.89% 17 6.1% Read the entire page →
From page 566... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 566 North Carolina North Carolina Site 1 Direction SB NB Volume Percentage Volume Percentage Passenger Car 349 70.42% 335 72.43% Pickups 110 22.21% 96 20.71% Single Unit 21 4.21% 16 3.5% Tractor-Trailer 16 3.16% 16 3.36% North Carolina Site 4 Direction SB NB Volume Percentage Volume Percentage Passenger Car 264 71.62% 400 71.23% Pickups 77 21.00% 128 22.83% Single Unit 11 2.88% 13 2.31% Tractor-Trailer 17 4.50% 20 3.63% North Carolina Site 7 Direction NB SB Volume Percentage Volume Percentage Passenger Car 289 66.71% 303 71.26% Pickups 99 22.85% 90 21.17% Single Unit 20 4.71% 15 3.57% Tractor-Trailer 25 5.72% 17 3.99% Read the entire page →
From page 567... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 567 Montana Montana Site 73 Direction EB WB Volume Percentage Volume Percentage Passenger Car 120 53.5% 141 59% Pickups 94 42% 86 36% Single Unit 10 4.5% 5 2% Tractor-Trailer 0 0% 7 3% Montana Site 132 Direction EB WB Volume Percentage Volume Percentage Passenger Car 71 46% 91 60.5% Pickups 62 40% 42 28% Single Unit 22 14% 17 11.5% Tractor-Trailer 0 0% 0 0% Idaho Idaho Site 44 Direction NB SB Volume Percentage Volume Percentage Passenger Car 121 67% 115 64% Pickups 26 14.5% 40 22.5% Single Unit 33 18.5% 24 13.5% Tractor-Trailer 0 0% 0 0% Idaho Site 47 Direction NB SB Volume Percentage Volume Percentage Passenger Car 213 71% 226 71% Pickups 54 18% 61 19% Single Unit 33 11% 32 10% Tractor-Trailer 0 0% 0 0% Read the entire page →
From page 568... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 568 Simulation Program Parameter Settings This section describes the respective input parameters that can be adjusted for each simulation tool to affect changes in the speed distribution, headway distribution, flow rate, and vehicle type split. SwashSim Speed Distribution The desired speed distribution is affected by two driver-specific characteristics and one vehiclespecific characteristic. Read the entire page →
From page 569... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 569 The corresponding input screen from SwashSim is shown below. Headway and Platoon Length Distribution In addition to the aforementioned desired speed distribution, the input vehicle demand will have a significant impact on the headway distribution. Read the entire page →
From page 570... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 570 It should be noted that SwashSim includes a variety of passenger cars and pickup trucks to provide for a more realistic representation of passenger vehicle mix in the actual traffic stream. Other general input parameters that affect the headway distribution include: • Car-following model parameters o For this, the main parameter of influence is the desired headway value. Read the entire page →
From page 571... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 571 • Distance traveled in the oncoming lane • Passing demand For the first two measures, SwashSim values were compared to those from NCHRP report 605 (Harwood et al., 2008) Read the entire page →
From page 572... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 572 The NCHRP report 605 does not directly report a passing rate measure. The total number of passing maneuvers is available, but other measures such as flow rates in each direction are reported on an aggregate level. Read the entire page →
From page 573... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 573 Where: P = Passing demand (passes/mi/h) q = directional traffic flow (veh/h) Read the entire page →
From page 574... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 574 Volume and Vehicle Type Split in Passing Lane Segments These values are influenced by the two algorithms/models described below. Also note that these algorithms/models will be influenced by the percentage of each driver type and the desired speed proportion by vehicle type entered into the input screens described previously. Read the entire page →
From page 575... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 575 Where: WTMO = willingness to move over, SVS = subject vehicle's desired speed (mi/h) , and FFS = link free-flow speed (mi/h) Read the entire page →
From page 576... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 576 The "Minimum desired speed (percent of speed limit) " value can also be set. Read the entire page →
From page 577... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 577 Other general input parameters that affect the headway distribution include: • Car-following model parameters: values were left at default values. • Minimum headway gap (s) Read the entire page →
From page 578... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 578 Read the entire page →
From page 579... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 579 Volume and vehicle-type split in passing lane segments For segments with a passing lane, the following input parameters are relevant: • Portion of desired speed distribution designated slow-moving vehicles (%) • Designate heavy vehicles as slow-moving vehicles • Passing vehicle changing to passing lane (%) Read the entire page →
From page 580... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 580 References Cohen, S Read the entire page →
From page 581... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 581 Comparison of Detector Field Data and Calibrated Simulation Detector Data Read the entire page →
From page 582... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 582 Site 11: Speed distribution in Eastbound Direction Vehicles are traveling in this direction (EB) Read the entire page →
From page 583... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 583 Regular lane Detector A Detector B Detector C Detector E Detector F Field data: * Data for Detector D were not valid due to detector failure. Read the entire page →
From page 584... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 584 SwashSim: TransModeler: Read the entire page →
From page 585... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 585 Site 11: Speed distribution in Westbound Direction (No passing lane) Vehicles are traveling in this direction (WB) Read the entire page →
From page 586... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 586 Regular lane Detector A Detector B Detector C Detector E Detector F Field data: * Data for Detector D were not valid due to detector failure. Read the entire page →
From page 587... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 587 Vehicles are traveling in this direction (EB) Read the entire page →
From page 588... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 588 Regular lane Detector A Detector B Detector C Detector E Detector F Field data: * Data for Detector D were not valid due to detector failure. Read the entire page →
From page 589... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 589 SwashSim: TransModeler: Site 11: Headway distribution in Westbound Direction (No passing lane) Read the entire page →
From page 590... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 590 Vehicles are traveling in this direction (WB) Read the entire page →
From page 591... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 591 Regular lane Detector A Detector B Detector C Detector E Detector F Field data: * Data for Detector D were not valid due to detector failure. Read the entire page →
From page 592... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 592 Vehicles are traveling in this direction (SB) Read the entire page →
From page 593... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 593 Detector A Detector B Detector C Detector D Detector E Detector F Field data: SwashSim: * See Calibration Note 1 TransModeler: Passing lane: Detector B Detector C Detector D Field data: Read the entire page →
From page 594... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 594 SwashSim: TransModeler: Read the entire page →
From page 595... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 595 Site 13: Speed distribution in Northbound Direction Vehicles are traveling in this direction (NB) Read the entire page →
From page 596... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 596 Detector A Detector B Detector C Detector D Detector E Detector F Field data: * See calibration note 2 SwashSim: TransModeler: Site 13: Headway distribution in Southbound Direction Read the entire page →
From page 597... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 597 Vehicles are traveling in this direction (SB) Read the entire page →
From page 598... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 598 Detector A Detector B Detector C Detector D Detector E Detector F Field data: SwashSim: * See calibration note 1 TransModeler: Passing lane: Detector B Detector C Detector D Field data: Read the entire page →
From page 599... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 599 SwashSim: * See calibration note 1 TransModeler: Read the entire page →
From page 600... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 600 Site 13: Headway distribution in Northbound Direction Vehicles are traveling in this direction (NB) Read the entire page →
From page 601... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 601 Detector A Detector B Detector C Detector D Detector E Detector F Field data: SwashSim: TransModeler: Site 17: Speed distribution in Southbound Direction Read the entire page →
From page 602... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 602 Vehicles are traveling in this direction (SB) Read the entire page →
From page 603... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 603 Detector A Detector B Detector C Detector D Detector E Detector F Field data: * Calibration Note 3 SwashSim: TransModeler: Detector G Detector H Detector I Detector J Detector K Detector L Field data: Read the entire page →
From page 604... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 604 SwashSim: TransModeler: Passing lane: Detector B Detector C Detector D Detector E Field data: Read the entire page →
From page 605... ... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 605 SwashSim: TransModeler: Read the entire page →

From page 106...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 106 Appendices Table of Contents A

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From page 107...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 107 H

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From page 108...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 108 List of Tables Table A-1. Average Ranking Score for Performance Measures ................................................

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From page 109...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 109 Table F-2. Coefficients Used in Speed-Flow Slope Model (Equation (F-4)

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From page 110...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 110 List of Figures Figure A-1. Agency Survey on Performance Measures .........................................................................

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From page 111...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 111 Figure D-13. Percent follower-flow curves for passing zone with 10 percent heavy vehicles in analysis direction.

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From page 112...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 112 Figure D-31. Performance measure-flow relationships for a vertical class 3, passing lane segment.

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From page 113...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 113 Figure F-11. Distribution of residuals from the speed-flow slope coefficient model by vertical alignment classification.

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From page 114...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 114 Figure I-7. Simulation Button on Toolbar ..................................................................................538 Figure I-8.

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From page 115...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 115 A Current Agency Practices and Preferences In order to better understand the transportation agencies' perception and preferences with regard to performance measures on two-lane highways, an online survey was designed as part of the NCHRP Project 17-65.

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From page 116...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 116 another measure introduced by the South African National Roads Agency and is calculated as the product of percent followers (PF) , defined earlier, and traffic density (Van As and Niekerk, 2004)

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From page 117...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 117

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From page 118...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 118

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From page 119...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 119

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From page 120...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 120

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From page 121...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 121

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From page 122...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 122

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From page 123...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 123

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From page 124...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 124

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From page 125...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 125

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From page 126...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 126 Figure A-1. Agency Survey on Performance Measures

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From page 127...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 127 A.2. Survey Responses A total of 41 responses were received, representing transportation agencies at 25 states and 4 Canadian provinces.

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From page 128...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 128 A.3.1. Agency Practice Use of Current HCM Methodology When asked about the use of HCM 2010 methodology for two-lane highways, all responding agencies in the U.S.

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From page 129...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 129 Data Collected In Support of Performance Measurement on Two-Lane Highways The survey asked participants about the data collected by their respective agencies that is used in assessing performance on two-lane highways. The results are summarized in Figure A-4.

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From page 130...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 130 As shown in this figure, the most important characteristic in a two-lane highway performance measure is being sensitive to traffic conditions, as perceived by survey participants. The second characteristic in importance is being sensitive to road conditions.

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From page 131...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 131 Figure A-6. Average ranking score of traffic flow aspects As Figure A-6 depicts, speed was ranked as the most useful aspect of traffic flow in assessing performance on two-lane highways.

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From page 132...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 132 Table A-1. Average Ranking Score for Performance Measures Traffic Flow Aspect Performance Measure Average Ranking Score Class I Class II Class III Flow Volume-to-Capacity (v/c)

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From page 133...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 133 While Table A-1 is useful in comparing performance measures that belong to the same group/category, it cannot be used to provide objective comparisons across categories. Specifically, the number of measures in each group is different, and therefore, the same average ranking in two different groups could indicate different levels of merit.

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From page 134...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 134 included a few questions about the agency experience with the use of the HCM and proposed changes and revisions to the current analytical procedures. A total of 35 usable responses were received, representing transportation agencies at 25 states and 4 Canadian provinces.

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From page 135...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 135 B Service Measure Evaluation B.1.

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From page 136...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 136 measures) , namely: percent time spent following (PTSF)

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From page 137...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 137 several miles long, there could be many changing conditions, such as posted speed limit and roadway alignment that affect ATS, yet it is not related to varying traffic conditions. In this section, a review of alternative performance measures that have been proposed in the literature or reported as part of current practice is presented.

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From page 138...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 138 In their article on the German experience, Brilon and Weiser (2006) reported the use of average speed of passenger cars over a longer stretch of highway, averaged over both directions, as a major performance measure on two-lane highways.

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From page 139...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 139 The most commonly used headway-based service measure is percent followers (PF)

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From page 140...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 140 B.3.5. Combination Measures A couple of measures proposed in the literature are associated with more than one traffic stream parameter, and as such, they are discussed independently from the previous measures.

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From page 141...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 141 • This criterion may be hard to satisfy as it is expected that different aspects of traffic operations are perceived as most important by drivers on different highway facilities. For example, while platooning on two-lane highways is a major determinant of the quality of operation, it is not a major factor in determining the quality of operations on other facilities.

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From page 142...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 142 Table B-1. Preliminary assessment matrix of performance measures on two-lane highways Performance Measure Type a (1)

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From page 143...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 143 B.5. Empirical Analysis of Field Data This section presents an empirical investigation into several two-lane highway performance measures that have been used in practice or proposed in the literature for operational analysis on two lane highways.

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From page 144...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 144 • Combined flow (veh/h) : The hourly flow rate in both directions of travel.

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From page 145...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 145 6. ATR 44, Highway U.S.

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From page 146...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 146 16. Site 17-OR, Highway U.S.

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From page 147...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 147 Table B-2. Description of Field Data at Study Sites Site name Dates Class Duration of data collection (hours)

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From page 148...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 148 ATR 28 ATR 43 ATR 73 ATR 132 Figure B-1. Montana data collection sites ATR 47 ATR 147 ATR 44 ATR 126 Figure B-2.

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From page 149...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 149 Site 17 Site 13 Site 2 Site 11 Figure B-3. Oregon data collection sites Site 1 Site 7 Site 4 Site 3 Figure B-4.

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From page 150...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 150 B.5.3. Research Underlying Hypotheses In this section, the major hypotheses underlying the relationship between performance measures and traffic variables are discussed.

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From page 151...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 151 performance measures investigated in this study and combined flow (combined flow in the two directions of travel)

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From page 152...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 152 Figure B-5. Scatterplots of performance measures vs combined flow

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From page 153...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 153 Figure B-6. Scatterplots of performance measures vs traffic split

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From page 154...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 154 Figure B-7. Scatterplots of performance measures vs speed variance

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From page 155...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 155 Figure B-8. Scatterplots of performance measures vs percent heavy vehicles

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From page 156...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 156 Correlation and Regression Analyses To get a better insight into the suitability of performance measures on different types of two-lane highways, three levels of analysis (data aggregation) were used in this study.

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From page 157...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 157 • Percent heavy vehicles exhibited very low correlation coefficients with all performance measures. • Again, headway-related performance measures generally exhibited high correlations with combined flow with coefficients greater than 0.8 for FD, FF, ID and IF.

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From page 158...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 158 Table B-5. Correlation analysis results for Class II data (1465 observations)

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From page 159...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 159 Table B-6. Correlation analysis results for Class III data (2294 observations)

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From page 160...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 160 Table B-7. Results from Multivariate Linear Regression Analysis for combined data Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split Percent HV Speed Variance Percent no passing Regression results for combined data ATS 0.10 5.55 63.41 0.00 –0.007 0.00 –2.25 0.00 –0.03 0.00 0.007 0.00 –0.01 0.00 ATS/FFS 0.06 0.02 1.008 0.00 –0.00002 0.00 –0.01 0.00 –0.0003 0.00 –0.00002 0.00 -- - % Follower 0.63 10.44 –4.45 0.00 0.06 0.00 26.9 0.00 0.12 0.00 -- - –0.13 0.00 Follower Flow 0.79 33.82 –94.33 0.00 0.27 0.00 127.22 0.00 0.16 0.00 –0.02 0.00 –0.15 0.00 Follower Density 0.79 0.6 –1.69 0.00 0.005 0.00 2.25 0.00 0.003 0.00 –0.0004 0.00 –0.0002 0.00 % Impeded 0.55 7.67 –2.96 0.00 0.03 0.00 16.49 0.00 0.08 0.00 0.004 0.00 –0.08 0.00 Impeded Flow 0.75 23.24 –58.07 0.00 0.17 0.00 77.42 0.00 0.12 0.00 –0.007 0.04 –0.08 0.00 Impeded Density 0.74 0.42 –1.05 0.00 0.003 0.00 1.38 0.00 0.002 0.00 –0.0001 0.01 –0.001 0.00 -Values in bold are inconsistent with the hypothesized logical relationship.

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From page 161...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 161 Table B-8. Results from Multivariate Linear Regression Analysis for class I sites Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split Percent HV Speed Variance Class 1 ATS 0.13 4.8 64.59 0.00 –0.007 0.00 –3.06 0.00 –0.03 0.00 0.004 0.00 ATS/FFS 0.08 0.02 1.01 0.00 –0.00002 0.00 –0.01 0.00 –0.0004 0.00 –0.00001 0.00 % Follower 0.57 11.49 –7.23 0.00 0.05 0.00 29.39 0.00 0.07 0.00 –0.008 0.00 Follower Flow 0.79 36.08 –118.37 0.00 0.29 0.00 163.67 0.00 -- - –0.03 0.00 Follower Density 0.79 0.64 –2.09 0.00 0.005 0.00 2.85 0.00 -- - –0.0005 0.00 % Impeded 0.48 8.41 –4.69 0.00 0.03 0.00 17.24 0.00 0.07 0.00 -- - Impeded Flow 0.75 25.04 –72.15 0.00 0.18 0.00 98.1 0.00 0.06 0.007 –0.01 0.00 Impeded Density 0.73 0.45 –1.29 0.00 0.003 0.00 1.72 0.00 0.001 0.01 –0.0002 0.00 -Values in bold are inconsistent with the hypothesized logical relationship.

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From page 162...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 162 Table B-10. Results from Multivariate Linear Regression Analysis for class III sites Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split Percent HV Speed Variance Class 3 ATS 0.03 6.74 60.72 0.00 –0.003 0.00 –5.06 0.00 –0.08 0.00 –0.02 0.03 ATS/FFS 0.11 0.01 1.009 0.00 –0.00001 0.00 –0.01 0.00 0.00007 0.03 0.0002 0.00 % Followers 0.75 7.9 –12.18 0.00 0.05 0.00 29.91 0.00 0.08 0.00 –0.04 0.00 Follower Flow 0.81 30.6 –110.86 0.00 0.25 0.00 144 0.00 0.66 0.00 –0.09 0.008 Follower Density 0.80 0.55 –2.09 0.00 0.004 0.00 2.75 0.00 0.01 0.00 -- - % Impeded 0.63 6.15 –8.61 0.00 0.03 0.00 19.52 0.00 0.05 0.001 -- - Impeded Flow 0.76 20.76 –68.72 0.00 0.15 0.00 90.38 0.00 0.39 0.00 -- - Impeded Density 0.76 0.38 –1.29 0.00 0.003 0.00 1.73 0.00 0.008 0.00 -- - -Values in bold are inconsistent with the hypothesized logical relationship.

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From page 163...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 163 Table B-12. Performance measures rank by class using R2 Performance Measure Sites Class I Class II Class III Rank Regression model R2 Rank Regression model R2 Rank Regression model R2 ATS 7 0.13 7 0.25 8 0.03 ATS/FFS 8 0.08 8 0.04 7 0.11 % Followers 5 0.57 5 0.27 5 0.75 Follower Flow 1 0.79 1 0.54 1 0.81 Follower Density 1 0.79 2 0.51 2 0.80 % Impeded 6 0.48 6 0.25 6 0.63 Impeded Flow 3 0.75 3 0.50 3 0.76 Impeded Density 4 0.73 4 0.48 4 0.76 Table B-13 shows performance measure rankings by R2 value using site-specific regression results.

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From page 164...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 164 Table B-14. Number of times variable found significant using site specific regression runs Performance Measure Combined Flow Traffic Split % Trucks Speed Variance ATS 15 8 8 14 ATS/FFS 14 7 4 14 % Follower 16 16 8 4 Follower Flow 16 16 5 5 Follower Density 16 16 5 5 % Impeded 16 16 9 10 Impeded Flow 16 16 5 8 Impeded Density 16 16 5 12 Table B-15 shows the number of times traffic variables were found significant for each performance measure using highway class regression runs.

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From page 165...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 165 B.6. Summary The results from the empirical analysis demonstrated that across all highway classes, follower density and follower flow had the highest correlation among several traffic variables.

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From page 166...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 166 B.6.1. Site Specific Regression Results (Class I)

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From page 167...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 167 Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance ATR 44 ID ATS 0.29 1.48 64.43 0.00 –0.002 0.00 1.2 0.003 -- - –0.03 0.00 ATS/FFS 0.13 0.01 1.009 0.00 –0.00002 0.00 –0.009 0.007 –0.0001 0.008 –0.00007 0.00 % Follower 0.71 7.14 –10.06 0.00 0.07 0.00 23.05 0.00 -- - -- - Follower Flow 0.83 15.9 –72.09 0.00 0.22 0.00 100.67 0.00 -- - 0.04 0.001 Follower Density 0.82 0.26 –1.16 0.00 0.003 0.00 1.6 0.00 -- - 0.0001 0.00 % Impeded 0.64 5.99 –7.65 0.00 0.05 0.00 14.96 0.00 -- - 0.02 0.00 Impeded Flow 0.77 12.97 –49.98 0.00 0.15 0.00 67.19 0.00 -- - 0.06 0.00 Impeded Density 0.76 0.21 –0.81 0.00 0.002 0.00 1.07 0.00 -- - 0.001 0.00 -Values in bold are inconsistent with the hypothesized logical relationship. Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance ATR 47 ID ATS 0.42 1.23 57 0.00 –0.004 0.00 -- - 0.01 0.03 –0.04 0.00 ATS/FFS 0.02 0.01 1.002 0.00 –0.000007 0.001 -- - -- - 0.00004 0.03 % Follower 0.69 6 –9.81 0.00 0.04 0.00 33.45 0.00 –0.08 0.007 –0.04 0.00 Follower Flow 0.85 18.14 –127.56 0.00 0.2 0.00 198.34 0.00 -- - –0.05 0.04 Follower Density 0.85 0.35 –2.43 0.00 0.004 0.00 3.7 0.00 -- - -- - % Impeded 0.61 4.8 –7.01 0.00 0.03 0.00 20.9 0.00 –0.05 0.04 –0.02 0.00 Impeded Flow 0.80 13.94 –82.17 0.00 0.13 0.00 124.26 0.00 -- - -- - Impeded Density 0.79 0.27 –1.56 0.00 0.002 0.00 2.32 0.00 -- - -- - -Values in bold are inconsistent with the hypothesized logical relationship.

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From page 168...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 168 Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 2-OR ATS 0.32 2.03 69.44 0.00 –0.006 0.00 –3.88 0.00 –0.06 0.00 –0.02 0.00 ATS/FFS 0.26 0.02 1.009 0.00 –0.00003 0.00 -- - -- - –0.0001 0.00 % Follower 0.63 9.13 -- - 0.08 0.00 19.47 0.00 -- - -- - Follower Flow 0.87 15.37 –65.04 0.00 0.28 0.00 80.15 0.00 -- - -- - Follower Density 0.86 0.26 –1.1 0.00 0.004 0.00 1.31 0.00 -- - -- - % Impeded 0.47 8.06 -- - 0.05 0.00 9.02 0.02 -- - 0.04 0.00 Impeded Flow 0.76 13.64 –40.07 0.00 0.16 0.00 42.91 0.00 -- - 0.05 0.009 Impeded Density 0.75 0.23 –0.68 0.00 0.003 0.00 0.71 0.00 -- - 0.0009 0.001 -Values in bold are inconsistent with the hypothesized logical relationship. Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 11-OR ATS 0.24 1.76 66.63 0.00 –0.005 0.00 –1.94 0.02 -- - –0.02 0.00 ATS/FFS 0.12 0.01 1.006 0.00 -- - -- - -- - –0.0001 0.00 % Follower 0.60 8.05 –12.58 0.00 0.07 0.00 33.85 0.00 -- - -- - Follower Flow 0.75 14.69 –49.27 0.00 0.19 0.00 69.88 0.00 -- - -- - Follower Density 0.75 0.23 –0.80 0.00 0.003 0.00 1.11 0.00 -- - -- - % Impeded 0.47 6.47 –8.64 0.00 0.04 0.00 19.6 0.00 -- - 0.04 0.006 Impeded Flow 0.69 10.22 –29.5 0.00 0.11 0.00 39.03 0.00 -- - -- - Impeded Density 0.68 0.16 –0.48 0.00 0.002 0.00 0.62 0.00 -- - 0.0008 0.02 -Values in bold are inconsistent with the hypothesized logical relationship.

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From page 169...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 169 Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 13-OR ATS 0.44 4.44 63.35 0.00 0.01 0.00 –8.51 0.001 –0.03 0.03 –0.03 0.00 ATS/FFS 0.28 0.06 1.07 0.00 -- - -- - –0.0007 0.00 –0.0002 0.00 % Follower 0.52 10.49 –18.47 0.00 0.07 0.00 19.92 0.001 0.36 0.00 0.03 0.001 Follower Flow 0.67 11.43 –44.72 0.00 0.17 0.00 44.48 0.00 0.32 0.00 -- - Follower Density 0.65 0.23 –0.9 0.00 0.003 0.00 0.9 0.00 0.006 0.00 0.0005 0.008 % Impeded 0.51 7.64 –12.02 0.00 0.05 0.00 11.27 0.007 0.22 0.00 0.03 0.00 Impeded Flow 0.65 8.88 –32.47 0.00 0.12 0.00 30.72 0.00 0.21 0.00 0.02 0.009 Impeded Density 0.65 0.17 –0.65 0.00 0.002 0.00 0.62 0.00 0.004 0.00 0.0005 0.00 -Values in bold are inconsistent with the hypothesized logical relationship. Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 17-OR ATS 0.20 2.01 65.48 0.00 0.001 0.03 -- - –0.05 0.00 –0.01 0.002 ATS/FFS 0.47 0.01 1.03 0.00 –0.00004 0.00 –0.03 0.00 –0.0001 0.006 –0.0002 0.00 % Follower 0.74 7.58 –19.2 0.00 0.05 0.00 36.62 0.00 0.13 0.00 -- - Follower Flow 0.75 33.62 –123.17 0.00 0.24 0.00 165.6 0.00 0.58 0.00 -- - Follower Density 0.75 0.53 –1.95 0.00 0.004 0.00 2.6 0.00 0.009 0.00 -- - % Impeded 0.67 5.51 –12.86 0.00 0.03 0.00 20.41 0.00 0.08 0.001 0.03 0.004 Impeded Flow 0.67 25.62 –79.23 0.00 0.15 0.00 97.1 0.00 0.41 0.00 -- - Impeded Density 0.66 0.41 –1.26 0.00 0.002 0.00 1.52 0.00 0.007 0.00 -- - -Values in bold are inconsistent with the hypothesized logical relationship.

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From page 170...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 170 Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 1-NC ATS 0.16 1.82 61.59 0.00 –0.001 0.00 -- - -- - –0.04 0.00 ATS/FFS 0.15 0.01 1.01 0.00 –0.00001 0.00 -- - -- - –0.0003 0.00 % Follower 0.85 7.45 -- - 0.05 0.00 19.16 0.00 0.09 0.03 -- - Follower Flow 0.92 31.45 –156.23 0.00 0.33 0.00 218 0.00 -- - 0.26 0.001 Follower Density 0.92 0.54 –2.72 0.00 0.006 0.00 3.7 0.00 -- - 0.006 0.00 % Impeded 0.7 6.75 -- - 0.03 0.00 8.2 0.004 0.11 0.002 0.11 0.00 Impeded Flow 0.88 23.93 –94.48 0.00 0.19 0.00 119.9 0.00 -- - 0.46 0.00 Impeded Density 0.87 0.42 –1.65 0.00 0.003 0.00 2.04 0.00 -- - 0.009 0.00 -Values in bold are inconsistent with the hypothesized logical relationship. Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 3-NC ATS 0.14 1.56 61.55 0.00 –0.003 0.00 –1.4 0.01 -- - -- - ATS/FFS 0.18 0.01 1.006 0.00 –0.00002 0.00 –0.01 0.03 -- - –0.0002 0.00 % Follower 0.67 12.49 6.71 0.01 0.07 0.00 26 0.00 –0.27 0.00 –0.13 0.00 Follower Flow 0.87 43.6 –294.25 0.00 0.45 0.00 373.3 0.00 -- - -- - Follower Density 0.77 0.87 –4.35 0.00 0.008 0.00 6.47 0.00 -- - -- - % Impeded 0.46 10.92 -- - 0.04 0.00 14.6 0.00 –0.17 0.007 -- - Impeded Flow 0.76 36 –142 0.00 0.25 0.00 207.8 0.00 -- - 0.21 0.04 Impeded Density 0.75 0.65 –2.49 0.00 0.004 0.00 3.62 0.00 -- - 0.004 0.02 -Values in bold are inconsistent with the hypothesized logical relationship.

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From page 171...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 171 Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 4-NC ATS 0.34 1.79 61.36 0.00 –0.004 0.00 –4.99 0.00 -- - –0.02 0.00 ATS/FFS 0.44 0.01 1.02 0.00 –0.00003 0.00 –0.02 0.00 -- - –0.0004 0.00 % Follower 0.84 7.15 –8.98 0.00 0.05 0.00 25.14 0.00 -- - -- - Follower Flow 0.87 39.96 –193.06 0.00 0.32 0.00 255.8 0.00 -- - 0.27 0.002 Follower Density 0.85 0.78 –3.74 0.00 0.006 0.00 4.87 0.00 -- - 0.007 0.00 % Impeded 0.73 6.73 –7.41 0.00 0.04 0.00 15.95 0.00 –0.12 0.001 0.09 0.00 Impeded Flow 0.80 33.56 –133.62 0.00 0.21 0.00 166.3 0.00 –0.35 0.05 0.46 0.00 Impeded Density 0.79 0.65 –2.59 0.00 0.004 0.00 3.18 0.00 -- - 0.009 0.00 -Values in bold are inconsistent with the hypothesized logical relationship.

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From page 172...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 172 B.6.2. Site Specific Regression Results (Class II)

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From page 173...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 173 B.6.3. Site Specific Regression Results (Class III)

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From page 174...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 174 Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance Site 7 - NC ATS 0.19 2.17 62.2 0.00 –0.002 0.00 –2 0.05 –0.02 0.03 –0.05 0.00 ATS/FFS 0.12 0.01 1.007 0.00 –0.000007 0.00 -- - -- - –0.0002 0.00 % Follower 0.85 7.45 –6.74 0.00 0.05 0.00 29.92 0.00 -- - –0.05 0.002 Follower Flow 0.90 30.56 –128.46 0.00 0.28 0.00 203.8 0.00 -- - -- - Follower Density 0.89 0.55 –2.3 0.00 0.005 0.00 3.53 0.00 -- - -- - % Impeded 0.69 6.74 –7.46 0.00 0.03 0.00 23.64 0.00 -- - -- - Impeded Flow 0.83 23.99 –81.4 0.00 0.16 0.00 129 0.00 -- - -- - Impeded Density 0.83 0.42 –1.46 0.00 0.003 0.00 2.24 0.00 -- - 0.002 0.01 -Values in bold are inconsistent with the hypothesized logical relationship.

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From page 175...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 175 C Identification of Viable Simulation Tools for the Analysis of Two-Lane Highways C.1.

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From page 176...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 176 • Ability to model two-lane highways, including passing in the oncoming lane and passing lanes. For those tools that had this ability, considerations included: o Flexibility in adjusting parameters for the applicable models, particularly for passing in a passing lane or the oncoming lane o Can slower or faster vehicles be specified to move into added lane of a passing lane section • Flexibility in modifying parameters affecting vehicle performance • Ability to include multiple point detectors along each link within the network • Robust performance measure output options • Level of documentation of modeling algorithms • Software tool is, or can be made, publicly available • Modern software architecture so that software tool will be able to run on a modern computer operating system for the foreseeable future • Technical support provided by the software developer C.3.1.

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From page 177...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 177 technical merit of the modeling algorithms, level of documentation of the modeling algorithms, software architecture, ease of use, and cost of the tool. We would appreciate it if you would respond to this message and answer the following questions: • Does your software tool have the capability to model any of the following two-lane highway operational features (please check all that apply)

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From page 178...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 178 o What is the cost of your tool (in US$) -- including the initial purchase price and any recurring license/maintenance fees?

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From page 179...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 179 greater realism for vehicle movement modeling than other simulation tools, particularly for commercial vehicles. Differences between SwashSim and CORSIM 6 include: • A 0.1-second simulation time resolution instead of 1 second for CORSIM 6.

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From page 180...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 180 Figure C-2. SwashSim network data entry screen Figure C-3.

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From page 181...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 181 can model and visualize the behavior of complex traffic systems in a 2-dimensional or 3dimensional GIS environment to illustrate and evaluate traffic flow dynamics, traffic signal and ITS operations, and overall network performance. TransModeler…integrates with TransCAD,…[a]

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From page 182...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 182 Figure C-5. TransModeler network coding screen (1)

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From page 183...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 183 D Modeling Speeds of Heavy Vehicles for Simulation Microscopic traffic simulation tools are frequently used to model traffic operations and assess traffic performance.

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From page 184...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 184 ft (100 to 200 m) before the curve, the radius of the curve, length of the approach tangent, grade of the approach tangent, and interaction between the length of the approach tangent and radius of the curve were all found to be significant predictors of the 85th percentile heavy vehicle speed.

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From page 185...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 185 Eck et al.

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From page 186...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 186 tangent, and length of the departure tangent were significant predictors of the 85th percentile curve speed at locations between the point of curvature (PC) and point of tangency (PT)

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From page 187...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 187 sight distances, they concluded that a decrease in the available sight distance increased the mean speed reduction. They also concluded that the traffic volume had a small effect on the mean speed reduction, but not enough to be meaningful.

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From page 188...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 188 and Collins (2000) used the curve speed equations developed by Fitzpatrick et al.

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From page 189...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 189 An R2 value was not reported for this model. Figueroa and Tarko (2007)

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From page 190...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 190 Table D-1. Desired Speed Proportions for Heavy Vehicles Heavy Vehicle Type Desired Speed Proportion Single-Unit Truck 0.98 Intermediate Semi-Trailer Truck 0.95 Interstate Semi-Trailer Truck 0.95 Double Semi-Trailer Truck 0.93 Upgrades Heavy vehicle speeds on upgrades were simulated using a full vehicle dynamics modeling approach.

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From page 191...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 191 multiple major components of the vehicle, including drivetrain components (e.g., engine and transmission) and suspension components, among others.

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From page 192...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 192 Figure D-1. Upgrade speed versus distance curves for a single-unit truck Figure D-2.

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From page 193...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 193 Figure D-3. Upgrade speed versus distance curves for an interstate semi-trailer truck After the speed versus distance curves were developed, a polynomial function was fit to the curves, excluding the constant crawl speed portion.

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From page 194...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 194 Table D-2. Upgrade Speed Model Coefficients for a Single-Unit Truck.

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From page 195...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 195 Table D-4. Upgrade Speed Model Coefficients for an Interstate Semi-Trailer Truck.

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From page 196...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 196 assuming an initial speed of 75 mi/h. These functions can be modified to produce upgrade speeds for different initial speeds.

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From page 197...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 197 1. Determine which upgrade speed function to use: Round the slope of the downgrade (in percent)

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From page 198...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 198 Table D-5. Additional Segment Lengths for Different Initial Speeds for a Single-Unit Truck.

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From page 199...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 199 Table D-7. Additional Segment Lengths for Different Initial Speeds for an Interstate SemiTrailer Truck.

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From page 200...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 200 Table D-9. Crawl Speeds and Corresponding Segment Lengths for an Intermediate SemiTrailer Truck.

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From page 201...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 201 D.4.2. Speeds on Curves Horizontal Curves Comparison of curve speed models.

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From page 202...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 202 Figure D-5. 85th percentile curve speeds of heavy vehicles entering from a tangent with an 85th percentile speed equal to 70 mi/h Figure D-6.

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From page 203...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 203 Figure D-7. 85th percentile curve speeds of heavy vehicles entering from a tangent with an 85th percentile speed equal to 50 mi/h As seen in these figures, the shape of the speed-radii curves for all of the models, except Donnell et al.'s (2001)

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From page 204...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 204 at speeds higher than the curve advisory speed (Bonneson et al., 2007; Chowdhury et al., 1991; Ritchie, 1972)

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From page 205...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 205 percentile tangent speed was assumed to be 11 percent larger than the average tangent speed. This was also based on findings in Bonneson et al.'s (2007)

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From page 206...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 206 speeds on vertical curves. Instead, modeling drivers' desire to travel above the posted speed and accounting for the impact of grade on heavy vehicle speeds was viewed as adequate for modeling vehicle speeds in the vicinity of a vertical curve.

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From page 207...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 207 D.5. Simulation Experimental Design This section describes the range of variables used to develop the proposed methodology.

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From page 208...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 208 (A)

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From page 209...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 209 D.5.2. Simulation Duration and Replications The simulation duration and number of replications can have a significant effect on the simulation results.

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From page 210...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 210 (A)

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From page 211...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 211 (A)

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From page 212...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 212 (A)

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From page 213...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 213 D.5.3. Effect of Opposing Heavy Vehicle Percentage on Passing Zone Segments Opportunities for passing in the opposing lane are largely dictated by the opposing traffic.

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From page 214...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 214 (A)

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From page 215...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 215 (A)

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From page 216...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 216 (A)

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From page 217...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 217 D.5.4. Maximum Analysis Flow Rates on Passing Lane Segments Passing lane segments can significantly improve traffic flow, especially on steep and long grades.

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From page 218...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 218 The trends deduced from Table D-12 are largely attributable to the merging of heavy vehicles at the end of the passing lane. As the heavy vehicle percentage increases, a larger number of heavy vehicles must merge.

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From page 219...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 219 Figure D-18 presents the results for vertical class 1, passing constrained segments with a length of 0.50 mi. This figure shows that there is a slight difference in the ATS for upgrades and downgrades when the heavy vehicle percentage and flow rate are both large.

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From page 220...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 220 (A)

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From page 221...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 221 (A)

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From page 222...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 222 (A)

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From page 223...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 223 (A)

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From page 224...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 224 (A)

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From page 225...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 225 (A)

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From page 226...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 226 (A)

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From page 227...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 227 (A)

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From page 228...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 228 (A)

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From page 229...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 229 (A)

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From page 230...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 230 (A)

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From page 231...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 231 (A)

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From page 232...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 232 (A)

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From page 233...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 233 (A)

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From page 234...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 234 (A)

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From page 235...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 235 D.5.6. Final Set of Parameters for Experimental Design The final set of variables and corresponding ranges of values for the experimental design are presented in Table D-13.

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From page 236...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 236 Table D-14. Directional Flow Rate Values for Varying Heavy Vehicle Percentages and Vertical Alignment Classifications (Passing Lane Segments)

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From page 237...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 237 E Approach for Estimating Follower Status E.1.

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From page 238...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 238 Figure E-1. Theoretical representation of following probability based on headway and speed Source: Catbagan and Nakamura (2010)

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From page 239...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 239 Figure E-2. Follower probability curve A second-order polynomial fit to these data yields the following function: (ℎ )

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From page 240...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 240 Figure E-3. Survival function and cumulative distribution function plots This survival function can be used directly for estimating following probabilities.

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From page 241...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 241 Step 4 Develop percent followers versus flow rate (for given roadway, traffic, and control factors) relationship; for example, as shown in the following figure.

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From page 242...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 242 Figure E-5. Follower density-flow rate relationship E.1.2.

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From page 243...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 243 value of 3 seconds was used in this study (same as PF)

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From page 244...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 244 reveal some of the patterns and trends that underlie those relationships. Then correlation and regression analyses were conducted to assess the level of association between performance measures and traffic variables.

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From page 245...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 245 Figure E-7. Correlation results of performance measures vs traffic variables Table E-2 shows the results of regression analysis for the study site using a 95% confidence level.

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From page 246...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 246 Table E-2. Results from Multivariate Linear Regression Analysis Performance Measure Regression Model Coefficients and P-value from t-test R2 SE Intercept Combined Flow Traffic Split % Trucks Speed Variance ATR 47 ATS 0.54 1.22 57.07 0.00 -0.004 0.00 -- -- 0.04 0.00 -0.03 0.00 ATS/FFS 0.04 0.01 1.01 0.00 -- -- -0.03 0.05 -- -- -- -- % Follower 0.68 6.75 -- -- 0.04 0.00 11.46 0.05 -- -- -0.07 0.00 % Followers-Nak 0.74 8.9 -- - 0.06 0.00 20.37 0.008 -- -- -- -- Follower Flow 0.86 15.95 -51.07 0.00 0.17 0.00 72.8 0.00 -- -- -0.11 0.01 Follower Density 0.86 0.3 -0.98 0.00 0.003 0.00 1.36 0.00 -- -- -0.002 0.04 % Impeded 0.56 5.68 -- -- 0.03 0.00 -- -- -- -- -0.04 0.01 Impeded Flow 0.79 13.55 -37.22 0.00 0.12 0.00 51.3 0.00 -- -- -- -- Impeded Density 0.79 0.26 -0.66 0.00 0.002 0.00 0.96 0.00 -- -- -- -- - Values in bold are inconsistent with the hypothesized logical relationship.

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From page 247...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 247 E.2. Following Status on Two-Lane Highways This study aimed to achieve a better understanding of the car-following interaction between vehicles on two-lane two-way highways.

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From page 248...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 248 less than hagg can generally be described as being in following state while those with headways greater than hcon can be described as being independent or in free-flow state. Typical values for the critical headway are expected to be in this range; i.e., between the boundary values hagg and hcon.

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From page 249...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 249 developing a procedure for determining the headway cut-off value used in estimating percent followers; that is, identifying the percentage of vehicles in car-following mode. The proposed procedure is based on the car-following process described earlier and the assumption that the percent followers are directly proportional to the reduction in average speed from that of freeflowing vehicles.

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From page 250...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 250 E.2.4. Headway Speed Investigation As car-following interaction between successive vehicles on the same lane is usually reflected in speed adjustments, speed data were used in examining the car-following parameters on two-lane highways, particularly the critical headway range and boundary values.

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From page 251...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 251 Figure E-9. Headway speed relationship at selected study sites

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From page 252...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 252 Figure E-10. Average speed for headways equal or greater than h at selected study sites E.2.5.

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From page 253...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 253 Figure E-11. Weibull distributions of speed vs headway at selected study sites Table E-4.

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From page 254...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 254 speed" in this analysis. For headways less than two seconds, the percentage of headways with relative speed of ±1 mi/h is more than 40%, which is relatively high given that each headway is associated with two vehicles in the traffic stream and therefore the percentage of "same speed" vehicles is expected to be higher than that of "same speed" headways (generally a function of platoon size)

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From page 255...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 255 The approach followed in this research is based on the premise that average speed and car following status are directly related. It was shown in the previous section that almost all vehicles with headways less than hagg are in car following mode and almost all vehicles with headways greater than hcon are in free-flow mode.

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From page 256...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 256 Assuming average speed in the transition range is directly proportional to percent followers, the frequencies of followers in this range can be determined, and calculations for ATR 32 are summarized in Table E-5. Table E-5.

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From page 257...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 257 The approach described above was applied to all fifteen study sites and the results are summarized in Table E-6. For class I highways, the estimated headway cut-off for percent followers varied between 1.8 and 2.8 seconds with the exception of ATR 92 where the cut-off value is much higher (3.845 seconds)

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From page 258...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 258 E.2.7. Summary of Findings This study presents an empirical investigation into the car-following interaction and the estimation of percent followers on rural two-lane highways.

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From page 259...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 259 F Analysis Methodology Model Development F.1.

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From page 260...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 260 The scatterplots also showed that passing designation influenced the FFS-heavy vehicle percentage relationship. Figure F-1 shows that heavy vehicles exerted a stronger influence on FFS for a passing constrained segment (Figure F-1A)

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From page 261...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 261 (A)

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From page 262...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 262 (A)

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From page 263...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 263 F.1.2. Free-Flow Speed Model Development Linear regression was used to fit a FFS model to the simulation data.

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From page 264...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 264 confidence level, and the adjusted R2 values ranged from 0.988 for vertical class 5 to 0.999 for vertical class 1. The coefficients for vertical class 1 are listed as "N/A" because the slope coefficient is constant for this vertical class.

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From page 265...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 265 Table F-1. Coefficients for FFS-HV% Slope Model (Used in Equation (F-2)

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From page 266...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 266 Table F-1 and Figure (F-5) also show that the BFFS exerted a stronger influence on the slope coefficient for higher vertical alignment classifications and larger opposing rates.

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From page 267...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 267 (A)

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From page 268...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 268 F.2. Models for Estimation of Average Speed Speed-flow relationships obtained from the final set of simulation data were evaluated to ensure the model form presented in Equation (2-6)

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From page 269...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 269 (A)

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From page 270...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 270 Figure F-9 shows that Equation (F-3) produced a better fit to the data than Equation (2-6)

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From page 271...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 271 where m = speed-flow slope coefficient (decimal) FFS = free-flow speed in the analysis direction (mi/h)

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From page 272...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 272 F-10A) than the vertical class 5 model (Figure F-10E)

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From page 273...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 273 Table F-2. Coefficients Used in Speed-Flow Slope Model (Equation (F-4)

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From page 274...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 274 Table F-4. Coefficients Used to Calculate b3 (Equation (F-5)

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From page 275...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 275 Table F-7. Coefficients Used to Calculate b4 (Equation (F-6)

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From page 276...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 276 (A)

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From page 277...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 277 (A)

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From page 278...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 278 (A)

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From page 279...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 279 (A)

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From page 280...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 280 (A)

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From page 281...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 281 (A)

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From page 282...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 282 (A)

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From page 283...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 283 Horizontal Curves For horizontal curves, the slope coefficient is estimated with Equation (F-7)

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From page 284...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 284 function of the vertical alignment classification and segment type, since the coefficients in these equations differ by vertical class and segment type. Table F-8 and Table F-9 present the coefficients for the passing zone/passing constrained segment models.

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From page 285...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 285 F.3. Models for Estimation of Percent Followers The model development process for the estimation of percent followers largely followed that for the average speed models.

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From page 286...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 286 where: b1–b7 = coefficient values, given in Table F-11, and Other terms as defined previously. Table F-11.

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From page 287...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 287 Table F-13. Coefficient Values for Equation (F-13)

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From page 288...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 288 F.4. Passing Lanes Passing is an important operational phenomenon on two-lane, two-way, highways.

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From page 289...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 289 Al-Kaisy and Freedman (2010)

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From page 290...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 290 In a study by Al-Kaisy and Freedman (2010) , the operational improvements downstream of passing lanes were investigated.

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From page 291...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 291 from a study by Al-Kaisy et al (2017)

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From page 292...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 292 miles, 3 miles, 4.7 miles and 7 miles beyond the end of the passing lane. There is another passing lane 4.9 miles after the taper end of the first passing lane.

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From page 293...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 293 Figure F-23. Performance measures along study sites For the calibration of the simulation tool, several outputs from the SwashSim were compared to the field data counterparts.

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From page 294...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 294 this table for comparison purposes. Overall, the average discrepancy for other performance measures is as favorable if not better than that of PF.

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From page 295...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 295 Table F-18. Traffic Simulation Output and Deviations from Field Measurements (Calibration)

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From page 296...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 296 Table F-19. Traffic Simulation Output and Deviations from Field Measurements (Validation)

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From page 297...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 297 For a %NP of 0, passing is allowed along the entire length of the facility, while for a %NP of 100, passing is not allowed in any part. For a %NP of 20, passing is allowed in 4 out of 5 consecutive segments, and so on.

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From page 298...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 298 study to determine the start of the flat portion of the curve; that is, the end of the passing lane effective length: • the percentage difference in FD between successive detector locations was found, • a 5-point moving average (average of the point of interest, two points upstream and two points downstream) of the percentage difference was used to dampen the fluctuations due to randomness in the simulation process (see Figure F-25)

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From page 299...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 299 Table F-20. Effective Length of Passing Lane Using Empirical Method (miles)

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From page 300...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 300 Where the effective length of passing lane is measured in miles, flow rate is measured in veh/h in the direction of analysis and %NP represents the percent-no passing on the two-lane highway for several miles upstream of the passing lane segment in the direction of analysis. As shown in Table F-20, using this cut-off value, the effective length would vary between 19.8 miles for flow rate of 200 veh/h and 0% no-passing and 5.8 miles for a flow rate of 800 veh/h and 100% no-passing zones.

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From page 301...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 301 DownstreamDistance = distance downstream from the start of the passing lane segment (mi) , %Followers = For the effective length calculation and downstream segment %Improve%Followers and %ImproveAvgSpeed calculations: % followers entering the passing lane segment (i.e., % followers estimated at the end of the segment just upstream of the passing lane segment; For the calculation of adjusted follower density downstream of the passing lane: % followers for the analysis segment, PassLaneLength = length of passing lane segment (mi)

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From page 302...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 302 performance measures within the passing lane, but leads to a faster rate of return to platooning downstream of the passing lane.

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From page 303...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 303 Wooldridge et al.

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From page 304...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 304 The two major analysis variables are traffic level and passing lane length. Other variables were held constant at their default values.

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From page 305...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 305 Station 1: 100' Upstream Station 2: 100' Downstream Station 3: 0.5 mi Downstream Figure F-26. Data collection setup, OR 2 and OR 17.

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From page 306...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 306 Satellite imagery data and GIS data were used to code the roadway network in SwashSim. Flow rates between 150-200, and 200-250 veh/h were used in calibrating the software.

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From page 307...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 307 Table F-24. Traffic Simulation Output and Deviations from Field Measurements (Calibration)

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From page 308...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 308 Table F-25. Traffic Simulation Output and Deviations from Field Measurements (Validation)

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From page 309...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 309 detectors were installed at 0.5, 0.75 and 1.25 miles downstream of the passing lane. The average outputs from these three detectors was used to estimate performance downstream of passing lane.

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From page 310...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 310 Figure F-27. Percent reduction in PF to length of passing lane (Harwood approach)

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From page 311...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 311 Proposed New Approach Due to the inconsistent results found using the maximum rate approach described in the previous section, a new approach was proposed and attempted in this investigation. In this approach, the optimum length of a passing lane is derived using the rate of change in performance as passing lane length is increased gradually using small fixed increments.

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From page 312...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 312 To identify the point at which the rate of performance improvement becomes constant (start of linear segment) , the best fit linear relationship was found while varying the length of the linear portion of the curve and the length with the best fit (highest R2)

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From page 313...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 313 the proposed approach correspond closely to the lengths provided by 22.5% and 25% reductions in PF. This finding is further illustrated in Figure F-30.

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From page 314...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 314 A linear regression model for percent reduction in PF was developed using traffic flow and passing lane length as explanatory variables as shown in the following equation: Percent Reduction in PF = 0.21 − 0.000218 × FlowRate + 0.09 × PassLaneLength (F-21) Where FlowRate equals traffic flow rate in veh/h and PassLaneLength equals the length of the passing lane, in miles.

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From page 315...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 315 Summary of Findings This task presents an investigation into the optimum length of passing lanes on two-lane-two way highways. The effect of traffic level on the optimum length of passing lanes was examined using a microscopic traffic simulation program called "SwashSim".

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From page 316...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 316 Refer to the truck speed-distance curves in Figure D-1, Figure D-2, and Figure D-3 to determine speed reduction on the grade. Alternatively, Equation (D-2)

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From page 317...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 317 Figure F-31. Schematic of example 2+1 configuration (passing vehicles use center lane)

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From page 318...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 318 F.5.1. Literature Review Europe The following information is summarized from a combination of the report "Application of European 2+1 Roadways Designs" (Potts and Harwood, 2003)

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From page 319...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 319 Figure F-34. Aerial photo of 2+1 site in Germany (Highway B169 south of Berlin)

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From page 320...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 320 • Finland o First 2+1 highway opened in 1991. o Guidelines for the transition lengths (buffer area between opposing passing lanes)

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From page 321...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 321 o 55 mi/h (90 km/h) typical posted speed limit.

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From page 322...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 322 Performance Measures • Germany o Traffic volumes range from 15,000 veh/day to 25,000 veh/day; the maximum traffic volume level observed was 30,000 veh/day. o Capacity: 1350 veh/h/ln (2-lane w/o passing lanes)

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From page 323...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 323 o Travel speeds at low flow rates were 0.6–1.2 mi/h (1–2 km/h) higher for the 2+1 roadway than for the two-lane cross section it replaced.

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From page 324...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 324 Sites in Kansas and Minnesota were used as case studies for collecting vehicle passing and geometry data over a 6-hour study period. The data were collected using cameras and counters and consisted of 15-minute vehicle counts and the following information on each vehicle: speed, headway, number of axles, direction, and time stamp.

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From page 325...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 325 Some of the conclusions reached either through field observation or simulation results include that a large numbers of vehicles began passing maneuvers at the beginning of the section but not all vehicles in the left lane actually used the left lane for passing. For example SH-121 showed 91.9% northbound and 65.9% southbound vehicles in the left lane passing and US-183 showed 24.9% northbound and 80.3% southbound vehicles in the left lane passing.

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From page 326...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 326 F.5.2. Simulation Tool Enhancements The SwashSim simulation tool was modified, such that for passing lane segments, either lane can be designated for use by passing vehicles.

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From page 327...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 327 experimental design. A total of 3 to 7 passing lanes were used in each direction of the evaluation segment depending on the length of passing lane segment.

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From page 328...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 328 Figure F-38. 2+1 network representation in SwashSim animation Station 1: 25 % of section length Station 2: 50 % of section length Station 3: 75 % of section length Station 4: 25 % of section length Station 5: 50 % of section length Station 6: 75 % of section length Transition segment (1000 ft)

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From page 329...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 329 Based on the simulation data obtained from the experimental design, the following models were obtained to estimate the change in performance between a 2+1 configuration and a comparable two-lane highway with no passing lanes, approximately 50% passing zones, and 16-18 miles in length.

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From page 330...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 330 F.6. Level of Service The service measures, and corresponding level of service (LOS)

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From page 331...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 331 • Run the experimental design with the batch processing utility in HCM-CALC (Figure F-40) for the HCM 2010 methodology.

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From page 332...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 332 follower density due to the lower speed. The LOS threshold values derived from this process are shown in Table F-35.

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From page 333...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 333 Follower density, for use with Table F-35 is calculated as follows.

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From page 334...

... Final Report 334 H Field Data Collection Supplemental Material Introduction Two-lane highway field data were an important aspect of the research approach.

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From page 335...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 335 North Carolina Sites Summary Location of Data Sites

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From page 336...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 336 Summary of North Carolina Field Data Collection Site ID Site Location Latitude Longitude Date Range Total Hours Number of Detectors Average Total Number of Vehicles (veh/detector) 1 US-43 34°56'28.16" -77°14'18.71" 06/08/201506/16/2015 186 6 84748 2 US-64 35°58'43.55" -78°35'12.95" 04/20/201504/28/2015 186 4 121753 3 US-17 35°52'10.55" -75°48'3.38" 06/15/201506/23/2015 187 5 39226 4 US-17 35°11'26.51" -77° 7'54.79" 06/09/201506/17/2015 187 5 96420 5 US-54 35°55'18.37" -79° 6'27.76" 05/18/201505/27/2015 187 5 120186 6 US-98 35°58'54.20" -78°44'31.88" 04/20/201504/28/2015 187 4 85417 7 US-17 35°16'46.86" -77° 7'18.13" 06/08/201506/16/2015 187 5 99644 Configuration of data collection equipment

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From page 337...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 337 Site 1: US 17/ NC 58, NC 58 to NC 58 Highway/Segment US 17/ NC 58, NC 58 to NC 58 County Jones Approximate AADT 12000 Truck Percentage SU 4.5%-MU 3.2% Passing Distance Long Passing Direction Both directions

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From page 338...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 338 Site 2: NC 98, Thompson Mill to Stony Hill Highway/Segment NC 98, Thompson Mill to Stony Hill County Wake Approximate AADT 15000 Truck Percentage SU 3.3%-MU 1.3% Passing Distance Short Passing Direction Both directions

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From page 339...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 339 Site 3: US 64, Columbia to US 264 Highway/Segment US 64, Columbia to US 264 County Tyrell, Dare Approximate AADT 3000-4000 High Seasonal Variation Highest daily volume (in summer) is around 10000 Truck Percentage SU 5.3%-MU 4.3% Passing Distance Long Passing Direction Both directions

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From page 340...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 340 Site 4: NC 43, NC 55 to Spring Garden Highway/Segment NC 43, NC 55 to Spring Garden County Craven Approximate AADT 17000 Truck Percentage SU 3.1%-MU 3.5% Passing Distance Short Passing Direction Some both ways

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From page 341...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 341 Site 5: NC 54, Old Fayetteville to Salem Church Highway/Segment NC 54, Old Fayetteville to Salem Church County Orange Approximate AADT 13000 Truck Percentage SU 2.6%-MU 2.2% Passing Distance Short Passing Direction Both directions

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From page 342...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 342 Site 6: NC 98, Old Creedmor to Patterson Highway/Segment NC 98, Old Creedmor to Patterson County Durham, Wake Approximate AADT 12000 Truck Percentage SU 1.9%-MU 1.5% Passing Distance Short Passing Direction Alternating directions

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From page 343...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 343 Site 7: NC 17/NC 43, Macedonia Church to US 17 Business Highway/Segment NC 17/NC 43, Macedonia Church to US 17 Business County Durham, Craven Approximate AADT 10000 High Seasonal Variation Volume on Friday in summer can be up to 35%-40% higher than AADT Truck Percentage SU 4.7%-MU 4.5% Passing Distance Medium Passing Direction Both directions

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From page 344...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 344 Site 8: NC 73, Club to McGuire Highway/Segment NC 73, Club to McGuire County Lincoln, Mecklenburg Approximate AADT 19000 Truck Percentage SU 3%-MU 1.3% Passing Distance Short Passing Direction Both directions

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From page 345...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 345 Oregon Sites Summary The main feature for locations chosen in Oregon is that all sites have passing lanes while there are not many driveways. Data were collected from two passing lane sites and two climbing lane sites (a passing lane on an upgrade section of roadway)

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From page 346...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 346 Site 2 Site 13 Site 11

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From page 347...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 347 Site 17

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From page 348...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 348 Detector locations Summary of Oregon Field Data Collection Site ID Site Location Latitude Longitude Date Range Total Hours Number of Detectors Average Total Number of Vehicles (veh/detector)

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From page 349...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 349 Sites with an upgrade section of passing lane (i.e., climbing lane) Count location 13: Sherman Hwy Highway/Segment Sherman Hwy Approximate AADT 2800 Truck AADT 1283 Truck Percentage SU 38.2% Passing Direction Both directions Number of lanes 3

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From page 350...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 350 Count location 17: Warm Springs Hwy Highway/Segment Warm Springs Hwy Approximate AADT 4300 Truck AADT 1306 Truck Percentage SU 20% Passing Direction Alternative direction Number of lanes 3

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From page 351...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 351 Sites with a level section of passing lane Count location 11: Mckenzie Hwy Highway/Segment Mckenzie Hwy Approximate AADT 4200 Truck AADT 364 Truck Percentage SU 9% Passing Direction Both directions Number of lanes 3

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From page 352...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 352 Count location 2: The Dalles-California Hwy Highway/Segment The Dalles-California Hwy Approximate AADT 3700 Truck AADT 1530 Truck Percentage SU 42.7% Passing Direction Both directions Number of lanes 4

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From page 353...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 353 Montana, Idaho Sites Summary ATR 28 ATR 43 ATR 73 ATR 132 Montana data collection sites

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From page 354...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 354 ATR 47 ATR 147 ATR 44 ATR 126 Idaho data collection sites

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From page 355...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 355 MSU: US 287 A MSU: US 191 MSU: US 287B Data collection setups at sample of Montana sites

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From page 356...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 356 Description of Field Data at Study Sites Site name Dates Class Duration of data collection (hours) Total vehicle count (veh)

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From page 357...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 357 California Site Summary A site was chosen for data collection SR-37 (Sears Point Rd) , north of San Francisco, because of its regular high traffic demands.

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From page 358...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 358 California, SR-37, data collection site Source: Google Earth

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From page 359...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 359 Data Processing The amount of field data collected in the project was voluminous. The Oregon and North Carolina sites each used multiple detectors, with each detector recording event-level data (i.e., data for each passing vehicle)

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From page 360...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 360 Screen which displays values and statistics for a large number of measures, in tabular form. Screen which displays values for a large number of measures, in graphical form: Histogram of all vehicle speeds

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From page 361...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 361 Histogram of speeds for two truck classes. Histogram of vehicle headways

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From page 362...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 362 Histogram of platoon lengths Speed versus flow rate graph

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From page 363...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 363 Speed versus flow rate graph ("zoomed in" flow rate axis)

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From page 364...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 364 Detector Data for North Carolina and Oregon Sites

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From page 365...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 365 Site 11: Speed-Flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: *

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From page 366...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 366 Site 11: Speed-Flow Relationship in Westbound (No passing lane) (East to the right)

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From page 367...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 367 Site 11: Percent follower-Flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: *

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From page 368...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 368 Site 11: Percent follower-Flow Relationship in Westbound (No passing lane) (East to the right)

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From page 369...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 369 Site 11: Percent follower–opposing flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: *

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From page 370...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 370 Site 11: Percent follower-opposing flow Relationship in Westbound (No passing lane) (East to the right)

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From page 371...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 371 Site 11: Follower density-Flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: *

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From page 372...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 372 Site 11: Follower density-Flow Relationship in Westbound (No passing lane) (East to the right)

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From page 373...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 373 Site 11: Follower density-opposing flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: *

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From page 374...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 374 Site 11: Follower density-opposing flow Relationship in Westbound (No passing lane) (East to the right)

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From page 375...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 375 Site 11: Percent impeded-Flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: *

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From page 376...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 376 Site 11: Percent impeded -Flow Relationship in Westbound (No passing lane) (East to the right)

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From page 377...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 377 Site 11: Percent impeded-opposing flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: *

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From page 378...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 378 Site 11: Percent impeded-opposing flow Relationship in Westbound (No passing lane) (East to the right)

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From page 379...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 379 Site 11: Impeded density-Flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: *

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From page 380...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 380 Site 11: Impeded density-Flow Relationship in Westbound (No passing lane) (East to the right)

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From page 381...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 381 Site 11: Impeded density-opposing flow Relationship in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: *

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From page 382...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 382 Site 11: Impeded density -opposing flow Relationship in Westbound (No passing lane) (East to the right)

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From page 383...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 383 Site 11: Headway distribution in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: *

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From page 384...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 384 Site 11: Headway distribution in Westbound (No passing lane) (East to the right)

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From page 385...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 385 Site 11: Speed distribution in Eastbound (East to the right) Regular Lane: Detector A Detector B Detector C Detector E Detector F Passing Lane: *

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From page 386...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 386 Site 11: Speed distribution in Westbound (No passing lane) (East to the right)

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From page 387...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 387 Site 13: Speed-flow Relationship in Southbound (5-min aggregation) (North to the left)

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From page 388...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 388 Site 13: Speed-flow Relationship in Northbound (No passing lane) (5-min aggregation)

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From page 389...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 389 Site 13: Percent follower-flow Relationship in Southbound (15-min aggregation) (North to the left)

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From page 390...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 390 Site 13: Percent follower-flow Relationship in Northbound (No passing lane) (15-min aggregation)

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From page 391...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 391 Site 13: Percent follower-opposing flow Relationship in Southbound (15-min aggregation) (North to the left)

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From page 392...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 392 Site 13: Percent follower-opposing flow Relationship in Northbound (No passing lane) (15-min aggregation)

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From page 393...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 393 Site 13: Follower density-flow Relationship in Southbound (15-min aggregation) (North to the left)

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From page 394...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 394 Site 13: Follower density-flow Relationship in Northbound (No passing lane) (15-min aggregation)

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From page 395...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 395 Site 13: Follower density-opposing flow Relationship in Southbound (15-min aggregation) (North to the left)

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From page 396...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 396 Site 13: Follower density-opposing flow Relationship in Northbound (No passing lane) (15-min aggregation)

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From page 397...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 397 Site 13: Percent impeded- flow Relationship in Southbound (15-min aggregation) (North to the left)

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From page 398...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 398 Site 13: Percent impeded-flow Relationship in Northbound (No passing lane) (15-min aggregation)

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From page 399...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 399 Site 13: Percent impeded-opposing flow Relationship in Southbound (15-min aggregation) (North to the left)

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From page 400...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 400 Site 13: Percent impeded-opposing flow Relationship in Northbound (No passing lane) (15-min aggregation)

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From page 401...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 401 Site 13: Impeded density-flow Relationship in Southbound (15-min aggregation) (North to the left)

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From page 402...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 402 Site 13: Impeded density-flow Relationship in Northbound (No passing lane) (15-min aggregation)

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From page 403...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 403 Site 13: Impeded density-opposing flow Relationship in Southbound (15-min aggregation) (North to the left)

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From page 404...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 404 Site 13: Impeded density-opposing flow Relationship in Northbound (No passing lane) (15-min aggregation)

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From page 405...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 405 Site 13: Headway distribution in Southbound (15-min aggregation) (North to the left)

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From page 406...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 406 Site 13: Headway distribution in Northbound (No passing lane) (15-min aggregation)

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From page 407...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 407 Site 13: Speed distribution in Southbound (15-min aggregation) (North to the left)

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From page 408...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 408 Site 13: Speed distribution in Northbound (No passing lane) (15-min aggregation)

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From page 409...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 409 Site 17: Speed-flow relationship in Southbound (15-min aggregation) (North to the left)

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From page 410...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 410 Site 17: Speed-flow relationship in Southbound (15-min aggregation) (Continued)

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From page 411...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 411 Site 17: Speed-flow relationship in Northbound (15-min aggregation) (North to the left)

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From page 412...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 412 Site 17: Speed-flow relationship in Northbound (No passing lane) (15-min aggregation)

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From page 413...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 413 Site 17: Percent follower-flow relationship in Southbound (15-min aggregation) (North to the left)

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From page 414...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 414 Site 17: Percent follower-flow relationship in Southbound (No passing lane) (15-min aggregation)

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From page 415...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 415 Site 17: Percent follower -flow relationship in Northbound (15-min aggregation) (North to the left)

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From page 416...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 416 Site 17: Percent follower -flow relationship in Northbound (No passing lane) (15-min aggregation)

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From page 417...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 417 Site 17: Percent follower-opposing flow relationship in Southbound (15-min aggregation) (North to the left)

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From page 418...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 418 Site 17: Percent follower-opposing flow relationship in Southbound (No passing lane) (15-min aggregation)

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From page 419...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 419 Site 17: Percent follower–opposing flow relationship in Northbound (15-min aggregation) (North to the left)

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From page 420...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 420 Site 17: Percent follower–opposing flow relationship in Northbound (No passing lane) (15-min aggregation)

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From page 421...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 421 Site 17: Follower density-flow relationship in Southbound (15-min aggregation) (North to the left)

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From page 422...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 422 Site 17: Follower density-flow relationship in Southbound (15-min aggregation) (Continued)

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From page 423...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 423 Site 17: Follower density-flow relationship in Northbound (15-min aggregation) (North to the left)

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From page 424...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 424 Site 17: Follower density-flow relationship in Northbound (No passing lane) (15-min aggregation)

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From page 425...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 425 Site 17: Follower density-opposing flow relationship in Southbound (15-min aggregation) (North to the left)

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From page 426...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 426 Site 17: Follower density-opposing flow relationship in Southbound (No passing lane) (15-min aggregation)

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From page 427...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 427 Site 17: Follower density–opposing flow relationship in Northbound (15-min aggregation) (North to the left)

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From page 428...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 428 Site 17: Follower density –opposing flow relationship in Northbound (No passing lane) (15-min aggregation)

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From page 429...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 429 Site 17: Percent impeded -flow relationship in Southbound (15-min aggregation) (North to the left)

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From page 430...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 430 Site 17: Percent impeded -flow relationship in Southbound (No passing lane) (15-min aggregation)

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From page 431...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 431 Site 17: Percent impeded -flow relationship in Northbound (15-min aggregation) (North to the left)

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From page 432...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 432 Site 17: Percent impeded-flow relationship in Northbound (No passing lane) (15-min aggregation)

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From page 433...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 433 Site 17: Percent impeded-opposing flow relationship in Southbound (15-min aggregation) (North to the left)

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From page 434...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 434 Site 17: Percent impeded-opposing flow relationship in Southbound (No passing lane) (15-min aggregation)

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From page 435...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 435 Site 17: Percent impeded –opposing flow relationship in Northbound (15-min aggregation) (North to the left)

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From page 436...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 436 Site 17: Percent impeded–opposing flow relationship in Northbound (No passing lane) (15-min aggregation)

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From page 437...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 437 Site 17: Impeded density-flow relationship in Southbound (15-min aggregation) (North to the left)

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From page 438...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 438 Site 17: Impeded density -flow relationship in Southbound (No passing lane) (15-min aggregation)

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From page 439...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 439 Site 17: Impeded density -flow relationship in Northbound (15-min aggregation) (North to the left)

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From page 440...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 440 Site 17: Impeded density-flow relationship in Northbound (No passing lane) (15-min aggregation)

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From page 441...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 441 Site 17: Impeded density -opposing flow relationship in Southbound (15-min aggregation) (North to the left)

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From page 442...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 442 Site 17: Impeded density -opposing flow relationship in Southbound (No passing lane) (15-min aggregation)

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From page 443...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 443 Site 17: Impeded density –opposing flow relationship in Northbound (15-min aggregation) (North to the left)

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From page 444...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 444 Site 17: Impeded density –opposing flow relationship in Northbound (No passing lane) (15-min aggregation)

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From page 445...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 445 Site 17: Headway distribution in Southbound (15-min aggregation) (North to the left)

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From page 446...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 446 Site 17: Headway distribution in Southbound (No passing lane) (15-min aggregation)

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From page 447...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 447 Site 17: Headway distribution in Northbound (15-min aggregation) (North to the left)

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From page 448...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 448 Site 17: Headway distribution in Northbound (No passing lane) (15-min aggregation)

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From page 449...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 449 Site 17: Speed distribution in Southbound (15-min aggregation) (North to the left)

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From page 450...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 450 Site 17: Speed distribution in Southbound (No passing lane) (15-min aggregation)

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From page 451...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 451 Site 17: Speed distribution in Northbound (15-min aggregation) (North to the left)

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From page 452...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 452 Site 17: Speed distribution in Northbound (No passing lane) (15-min aggregation)

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From page 453...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 453 North Carolina Sites Data Summary

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From page 454...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 454 Summary of North Carolina Field Data Collection Site ID Site Location Latitude Longitude Date Range Total Hours Number of Detectors Average Total Number of Vehicles 1 US-43 34°56'28.16" -77°14'18.71" 06/08/201506/16/2015 186 6 84748 2 US-64 35°58'43.55" -78°35'12.95" 04/20/201504/28/2015 186 4 121753 3 US-17 35°52'10.55" -75°48'3.38" 06/15/201506/23/2015 187 5 39226 4 US-17 35°11'26.51" -77° 7'54.79" 06/09/201506/17/2015 187 5 96420 5 US-54 35°55'18.37" -79° 6'27.76" 05/18/201505/27/2015 187 5 120186 6 US-98 35°58'54.20" -78°44'31.88" 04/20/201504/28/2015 187 4 85417 7 US-17 35°16'46.86" -77° 7'18.13" 06/08/201506/16/2015 187 5 99644

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From page 455...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 455 Site 4: Speed-flow Relationship (North to the left) (5-min aggregation)

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From page 456...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 456 Site 4: Percent follower-flow Relationship (North to the left) (15-min aggregation)

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From page 457...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 457 Site 4: Percent follower-opposing flow Relationship (North to the left) (15-min aggregation)

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From page 458...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 458 Site 4: Follower density-flow Relationship (North to the left) (15-min aggregation)

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From page 459...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 459 Site 4: Follower density-opposing flow Relationship (North to the left) (15-min aggregation)

Read the entire page →

From page 460...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 460 Site 4: Impeded density-flow Relationship (North to the left) (15-min aggregation)

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From page 461...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 461 Site 4: Impeded density-opposing flow Relationship (North to the left) (15-min aggregation)

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From page 462...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 462 Site 4: Percent impeded-flow Relationship (North to the left) (15-min aggregation)

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From page 463...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 463 Site 4: Percent impeded-opposing flow Relationship (North to the left) (15-min aggregation)

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From page 464...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 464 Site 4: Headway distribution (North to the left) NB: Detector A Detector B Detector C Detector D Detector E SB: Detector A Detector B Detector C Detector D Detector E

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From page 465...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 465 Site 4: Speed distribution (North to the left) NB: Detector A Detector B Detector C Detector D Detector E SB: Detector A Detector B Detector C Detector D Detector E

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From page 466...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 466 Site 1: Speed-flow Relationship (North to the left) (5-min aggregation)

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From page 467...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 467 Site 1: Percent follower-flow Relationship (North to the left) (15-min aggregation)

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From page 468...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 468 Site 1: Percent follower-opposing flow Relationship (North to the left) (15-min aggregation)

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From page 469...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 469 Site 1: Follower density-flow Relationship (North to the left) (15-min aggregation)

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From page 470...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 470 Site 1: Follower density-opposing flow Relationship (North to the left) (15-min aggregation)

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From page 471...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 471 Site 1: Impeded density-flow Relationship (North to the left) (15-min aggregation)

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From page 472...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 472 Site 1: Impeded density-opposing flow Relationship (North to the left) (15-min aggregation)

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From page 473...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 473 Site 1: Percent impeded-flow Relationship (North to the left) (15-min aggregation)

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From page 474...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 474 Site 1: Percent impeded-opposing flow Relationship (North to the left) (15-min aggregation)

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From page 475...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 475 Site 1: Headway distribution (North to the left) NB: Detector A Detector B Detector C Detector D Detector E Detector F SB: Detector A Detector B Detector C Detector D Detector E Detector F

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From page 476...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 476 Site 1: Speed distribution (North to the left) NB: Detector A Detector B Detector C Detector D Detector E Detector F SB: Detector A Detector B Detector C Detector D Detector E Detector F

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From page 477...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 477 Site 2: Speed-flow Relationship (East to the right) (5-min aggregation)

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From page 478...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 478 Site 2: Percent follower-flow Relationship (East to the right) (15-min aggregation)

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From page 479...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 479 Site 2: Percent follower-opposing flow Relationship (East to the right) (15-min aggregation)

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From page 480...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 480 Site 2: Follower density-flow Relationship (East to the right) (15-min aggregation)

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From page 481...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 481 Site 2: Follower density-opposing flow Relationship (East to the right) (15-min aggregation)

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From page 482...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 482 Site 2: Impeded density-flow Relationship (East to the right) (15-min aggregation)

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From page 483...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 483 Site 2: Impeded density-opposing flow Relationship (East to the right) (15-min aggregation)

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From page 484...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 484 Site 2: Percent impeded-flow Relationship (East to the right) (15-min aggregation)

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From page 485...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 485 Site 2: Percent impeded-opposing flow Relationship (East to the right) (15-min aggregation)

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From page 486...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 486 Site 2: Headway distribution (East to the right) EB: Detector A Detector B Detector C Detector D WB: Detector A Detector B Detector C Detector D

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From page 487...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 487 Site 2: Speed distribution (East to the right) EB: Detector A Detector B Detector C Detector D WB: Detector A Detector B Detector C Detector D

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From page 488...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 488 Site 3: Speed-flow Relationship (East to the left) (5-min aggregation)

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From page 489...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 489 Site 3: Percent follower-flow Relationship (East to the left) (15-min aggregation)

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From page 490...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 490 Site 3: Percent follower-opposing flow Relationship (East to the left) (15-min aggregation)

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From page 491...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 491 Site 3: Follower density-flow Relationship (East to the left) (15-min aggregation)

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From page 492...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 492 Site 3: Follower density-opposing flow Relationship (East to the left) (15-min aggregation)

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From page 493...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 493 Site 3: Impeded density-flow Relationship (East to the left) (15-min aggregation)

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From page 494...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 494 Site 3: Impeded density-opposing flow Relationship (East to the left) (15-min aggregation)

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From page 495...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 495 Site 3: Percent impeded-flow Relationship (East to the left) (15-min aggregation)

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From page 496...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 496 Site 3: Impeded density-opposing flow Relationship (East to the left) (15-min aggregation)

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From page 497...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 497 Site 3: Headway distribution (East to the left) EB: Detector A Detector B Detector C Detector D Detector E WB: Detector A Detector B Detector C Detector D Detector E

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From page 498...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 498 Site 3: Speed distribution (East to the left) EB: Detector A Detector B Detector C Detector D Detector E WB: Detector A Detector B Detector C Detector D Detector E

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From page 499...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 499 Site 5: Speed-flow Relationship (East to the left) (5-min aggregation)

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From page 500...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 500 Site 5: Percent follower-flow Relationship (East to the left) (15-min aggregation)

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From page 501...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 501 Site 5: Percent follower-opposing flow Relationship (East to the left) (15-min aggregation)

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From page 502...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 502 Site 5: Follower density-flow Relationship (East to the left) (15-min aggregation)

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From page 503...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 503 Site 5: Follower density-opposing flow Relationship (East to the left) (15-min aggregation)

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From page 504...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 504 Site 5: Impeded density-flow Relationship (East to the left) (15-min aggregation)

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From page 505...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 505 Site 5: Impeded density-opposing flow Relationship (East to the left) (15-min aggregation)

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From page 506...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 506 Site 5: Percent impeded-flow Relationship (East to the left) (15-min aggregation)

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From page 507...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 507 Site 5: Percent impeded-opposing flow Relationship (East to the left) (15-min aggregation)

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From page 508...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 508 Site 5: Headway distribution (East to the left) EB: Detector A Detector B Detector C Detector D Detector E WB: Detector A Detector B Detector C Detector D Detector E

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From page 509...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 509 Site 5: Speed distribution (East to the left) EB: Detector A Detector B Detector C Detector D Detector E WB: Detector A Detector B Detector C Detector D Detector E

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From page 510...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 510 Site 6: Speed-flow Relationship (East to the right) (5-min aggregation)

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From page 511...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 511 Site 6: Percent follower-flow Relationship (East to the right) (15-min aggregation)

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From page 512...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 512 Site 6: Percent follower-opposing flow Relationship (East to the right) (15-min aggregation)

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From page 513...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 513 Site 6: Follower density-flow Relationship (East to the right) (15-min aggregation)

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From page 514...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 514 Site 6: Follower density-opposing flow Relationship (East to the right) (15-min aggregation)

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From page 515...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 515 Site 6: Impeded density-flow Relationship (East to the right) (15-min aggregation)

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From page 516...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 516 Site 6: Impeded density-opposing flow Relationship (East to the right) (15-min aggregation)

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From page 517...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 517 Site 6: Percent impeded-flow Relationship (East to the right) (15-min aggregation)

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From page 518...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 518 Site 6: Percent impeded-opposing flow Relationship (East to the right) (15-min aggregation)

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From page 519...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 519 Site 6: Headway distribution (East to the right) EB: Detector A Detector B Detector C Detector D WB: Detector A Detector B Detector C Detector D

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From page 520...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 520 Site 6: Speed distribution (East to the right) EB: Detector A Detector B Detector C Detector D WB: Detector A Detector B Detector C Detector D

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From page 521...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 521 Site 7: Speed-flow Relationship (North to the right) (5-min aggregation)

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From page 522...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 522 Site 7: Percent follower-flow Relationship (North to the right) (15-min aggregation)

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From page 523...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 523 Site 7: Percent follower-opposing flow Relationship (North to the right) (15-min aggregation)

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From page 524...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 524 Site 7: Follower density-flow Relationship (North to the right) (15-min aggregation)

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From page 525...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 525 Site 7: Follower density-opposing flow Relationship (North to the right) (15-min aggregation)

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From page 526...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 526 Site 7: Impeded density-flow Relationship (North to the right) (15-min aggregation)

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From page 527...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 527 Site 7: Impeded density-opposing flow Relationship (North to the right) (15-min aggregation)

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From page 528...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 528 Site 7: Percent impeded-flow Relationship (North to the right) (15-min aggregation)

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From page 529...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 529 Site 7: Percent impeded-opposing flow Relationship (North to the right) (15-min aggregation)

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From page 530...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 530 Site 7: Headway distribution (North to the right) NB: Detector A Detector B Detector C Detector D Detector E SB: Detector A Detector B Detector C Detector D Detector E

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From page 531...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 531 Site 7: Speed distribution (North to the right) NB: Detector A Detector B Detector C Detector D Detector E SB: Detector A Detector B Detector C Detector D Detector E

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From page 532...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 532 I Simulation Tools Supplemental Material Developing a Two-Lane Highway Simulation in SwashSim After you have installed the program, double-click on the SwashSim icon on your desktop or within the ‘Start' menu.

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From page 533...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 533 Figure I-2. Project Selection Dialog Main Input Screen The main input screen (Figure 3)

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From page 534...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 534 Segment Input Fields Links and their corresponding characteristics are specified for the west-to-east or north-to-south travel direction and the inputs for the opposing travel direction are automatically created. Upstream/Downstream Node ID • Each two-lane highway segment has a beginning and ending node.

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From page 535...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 535 Free-Flow Speed Method For tangent links, the free-flow speed must be entered directly. For curved links, the free-flow speed can be entered directly or it can be estimated.

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From page 536...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 536 Detectors Detectors allow one to set points along the segment to measure specific items, such as speed, volume, etc. To set detectors on a segment click on ‘Set' under ‘Set Detector(s)

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From page 537...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 537 Figure I-5. Traffic Data Toolbar Button Figure I-6.

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From page 538...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 538 Saving a Project File To save your project input values to a file, select ‘Save' from the ‘File' menu. The name of the saved file will be displayed in the upper-right corner of the main inputs screen.

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From page 539...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 539 Figure I-8. Simulation Control Panel (Single Run)

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From page 540...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 540 Warm-up Time This field dictates how long the traffic simulation will run before performance measurement data are collected. Enter a number between 1 and 1800 seconds.

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From page 541...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 541 simulation time have been simulated. When the simulation run has completed, the textbox will also show the total computer run time and the number of vehicles that were generated.

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From page 542...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 542 Figure I-12. Animation Screen (2)

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From page 543...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 543 Figure I-13. Vehicle Properties Form

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From page 544...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 544 Developing a Two-Lane Highway Simulation in TransModeler Create a New Simulation  Select "New File" on far left of standard toolbar  Select "With a New Simulation Database"  On Confirm screen select "No" to continue without creating a map  Create file name, save, and begin Creating Segments on TransModeler  Add links (Under ‘Streets' tab in TransModeler Sidebar) • Double-Click to set link • Right click to Un-Do link placement • Press "Esc" button to escape function

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From page 545...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 545 Figure I-14. TransModeler Sidebar  Save Edits after adding links Figure I-15.

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From page 546...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 546 Figure I-16. Defining Links • Under ‘Lane' tab change Lane Changing to Left to Allowed.

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From page 547...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 547  Select the Edit Class box under Link Attributes and the "Edit Road Class" box will open Figure I-18. Edit Road Class  From this box the Speed Limit can be set, which is the main factor for speed within network for simulation  Desired Speed Distribution can also be selected from this window.

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From page 548...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 548 Adding Centroids (Traffic Flow) In the transportation planning context, "centroids" are nodes in a transportation network that represent a geographic area called a traffic analysis zone (TAZ)

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From page 549...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 549 Figure I-21. Centroid Direction  Add centroid to network by selecting the ‘Add Centroid' in TransModeler Sidebar and then selecting the link to place it on.

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From page 550...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 550 Adding Lanes  Lanes can be added under the Streets Tab of the TransModeler Sidebar Figure I-22. Lanes  Select the ‘Add a Lane' button and then select the road in which to add lane  Select ‘Save Edits' once complete Adding Lane Connectors  Lane connectors direct the flow of traffic on lanes and links  Select ‘Add a Lane Connector' under the Streets Tab of the TransModeler Sidebar Figure 22  Select lane in which to place connector, and if it is suitable for the simulation TransModeler will allow the addition of the lane connector Elevation  To edit elevation select the in the Trans Modeler Sidebar Figure I-23.

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From page 551...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 551 Figure I-24. Elevation Creating and Adding Trip Matrix (Traffic Flow)

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From page 552...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 552 Figure I-26. Trip Matrix: Origin & Destinations  Create Matrix name and Save  A "Trip Matrix Settings" box will appear where Setup and Content can be added  Under the "Content" Tab more matrices can be added with specification on vehicle type  Once Setup/Content is complete a blank graph will appear Figure I-27.

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From page 553...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 553 Adding  To add and edit trip matrices select "Project Settings" on the TransModeler sidebar under the Simulation Tab Figure I-29. Project Settings  Under the input tab in "Project Settings" the list of Trip Tables used for the network will be displayed.

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From page 554...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 554 Passing  Located under Simulation > Parameters > Driver Behavior Figure I-31. Passing  Select Passing > Choose General Before a subject vehicle will consider passing in the opposite direction, certain conditions must be met: • The driver must be traveling at a speed a certain threshold, the minimum desired speed deficit, below its desired speed.

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From page 555...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 555 • A distance downstream derived from a minimum time headway and its current speed (i.e., distance = current speed * minimum time headway)

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From page 556...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 556 Designating Passing Lanes  After adding lanes to a segment, passing lanes can be designated  With the ‘Info' button click the lane that should be the passing lane Figure I-32. Info  Within the Edit Road Properties box select the ‘Lanes' tab.

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From page 557...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 557 Figure I-34. Adding Sensors  Select location on network to place sensor and specify properties in the "Edit Sensor Properties" box Figure I-35.

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From page 558...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 558 Figure I-36. Save Edits Outputs  To edit outputs select "Project Settings" under the Simulation tab of the TransModeler Sidebar.

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From page 559...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 559 Figure I-38. Output Tab on TransModeler Sidebar  Select Group and Report type from drop downs to specify what outputs to present  Select ‘Create Report' to create Output Report Figure I-39.

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From page 560...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 560  Under the Output tab of the "Project Settings" box make sure ‘Playback' is selected Figure 37  To access playbacks select "Simulation Settings" under Simulation tab of TransModeler Sidebar Figure I-40. Simulation Settings  In the Simulation Settings box select ‘Playback' and the skip increments (time between frames)

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From page 561...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 561 Figure I-42. Begin Playback

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From page 562...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 562 Simulation Calibration Traffic simulation models are powerful tools that require calibration and validation. Calibration adjusts simulation parameters so the simulation outputs agree well with ground truth conditions.

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From page 563...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 563 somewhat different parameter values across the sites due to varying characteristics across sites. All of these settings were used to guide the selection of proper/reasonable parameter settings for the networks developed to use for the experimental design to generate the performance measure functions/relationships.

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From page 564...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 564 Oregon Site ID Time Interval Total Detectors 11 16:00-17:00 6 13 13:00-14:00 6 17 15:00-16:00 12 North Carolina Site ID Time Interval Total Detectors 1 16:00-17:00 6 4 16:00-17:00 5 7 16:00-17:00 5 Montana Site ID Time Interval Total Detectors 132 11:00-12:00 1 73 10:00-11:00 1 Idaho Site ID Time Interval Total Detectors 47 10:00-11:00 1 44 9:00-10:00 1 The data analysis revealed that the two most prevalent heavy vehicle categories were single-unit trucks and tractor+semi-trailer trucks (commonly referred to as tractor-trailers)

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From page 565...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 565 Oregon Oregon Site 11 Direction WB EB Volume Percentage Volume Percentage Passenger Car 114 64.43% 136 59.35% Pickups 35 19.96% 54 23.38% Single Unit 17 9.84% 28 12.24% Tractor-Trailer 10 5.77% 12 5.03% Oregon Site 13 Direction SB NB Volume Percentage Volume Percentage Passenger Car 63 54.49% 67 59.76% Pickups 14 12.03% 18 16.24% Single Unit 12 10.58% 9 7.9% Tractor-Trailer 26 22.9% 18 16.1% Oregon Site 17 Direction SB NB Volume Percentage Volume Percentage Passenger Car 178 70.25% 190 69.82% Pickups 43 17.04% 45 16.63% Single Unit 20 7.82% 20 7.45% Tractor-Trailer 12 4.89% 17 6.1%

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From page 566...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 566 North Carolina North Carolina Site 1 Direction SB NB Volume Percentage Volume Percentage Passenger Car 349 70.42% 335 72.43% Pickups 110 22.21% 96 20.71% Single Unit 21 4.21% 16 3.5% Tractor-Trailer 16 3.16% 16 3.36% North Carolina Site 4 Direction SB NB Volume Percentage Volume Percentage Passenger Car 264 71.62% 400 71.23% Pickups 77 21.00% 128 22.83% Single Unit 11 2.88% 13 2.31% Tractor-Trailer 17 4.50% 20 3.63% North Carolina Site 7 Direction NB SB Volume Percentage Volume Percentage Passenger Car 289 66.71% 303 71.26% Pickups 99 22.85% 90 21.17% Single Unit 20 4.71% 15 3.57% Tractor-Trailer 25 5.72% 17 3.99%

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From page 567...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 567 Montana Montana Site 73 Direction EB WB Volume Percentage Volume Percentage Passenger Car 120 53.5% 141 59% Pickups 94 42% 86 36% Single Unit 10 4.5% 5 2% Tractor-Trailer 0 0% 7 3% Montana Site 132 Direction EB WB Volume Percentage Volume Percentage Passenger Car 71 46% 91 60.5% Pickups 62 40% 42 28% Single Unit 22 14% 17 11.5% Tractor-Trailer 0 0% 0 0% Idaho Idaho Site 44 Direction NB SB Volume Percentage Volume Percentage Passenger Car 121 67% 115 64% Pickups 26 14.5% 40 22.5% Single Unit 33 18.5% 24 13.5% Tractor-Trailer 0 0% 0 0% Idaho Site 47 Direction NB SB Volume Percentage Volume Percentage Passenger Car 213 71% 226 71% Pickups 54 18% 61 19% Single Unit 33 11% 32 10% Tractor-Trailer 0 0% 0 0%

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From page 568...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 568 Simulation Program Parameter Settings This section describes the respective input parameters that can be adjusted for each simulation tool to affect changes in the speed distribution, headway distribution, flow rate, and vehicle type split. SwashSim Speed Distribution The desired speed distribution is affected by two driver-specific characteristics and one vehiclespecific characteristic.

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From page 569...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 569 The corresponding input screen from SwashSim is shown below. Headway and Platoon Length Distribution In addition to the aforementioned desired speed distribution, the input vehicle demand will have a significant impact on the headway distribution.

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From page 570...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 570 It should be noted that SwashSim includes a variety of passenger cars and pickup trucks to provide for a more realistic representation of passenger vehicle mix in the actual traffic stream. Other general input parameters that affect the headway distribution include: • Car-following model parameters o For this, the main parameter of influence is the desired headway value.

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From page 571...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 571 • Distance traveled in the oncoming lane • Passing demand For the first two measures, SwashSim values were compared to those from NCHRP report 605 (Harwood et al., 2008)

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From page 572...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 572 The NCHRP report 605 does not directly report a passing rate measure. The total number of passing maneuvers is available, but other measures such as flow rates in each direction are reported on an aggregate level.

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From page 573...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 573 Where: P = Passing demand (passes/mi/h) q = directional traffic flow (veh/h)

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From page 574...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 574 Volume and Vehicle Type Split in Passing Lane Segments These values are influenced by the two algorithms/models described below. Also note that these algorithms/models will be influenced by the percentage of each driver type and the desired speed proportion by vehicle type entered into the input screens described previously.

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From page 575...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 575 Where: WTMO = willingness to move over, SVS = subject vehicle's desired speed (mi/h) , and FFS = link free-flow speed (mi/h)

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From page 576...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 576 The "Minimum desired speed (percent of speed limit) " value can also be set.

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From page 577...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 577 Other general input parameters that affect the headway distribution include: • Car-following model parameters: values were left at default values. • Minimum headway gap (s)

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From page 578...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 578

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From page 579...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 579 Volume and vehicle-type split in passing lane segments For segments with a passing lane, the following input parameters are relevant: • Portion of desired speed distribution designated slow-moving vehicles (%) • Designate heavy vehicles as slow-moving vehicles • Passing vehicle changing to passing lane (%)

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From page 580...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 580 References Cohen, S

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From page 581...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 581 Comparison of Detector Field Data and Calibrated Simulation Detector Data

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From page 582...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 582 Site 11: Speed distribution in Eastbound Direction Vehicles are traveling in this direction (EB)

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From page 583...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 583 Regular lane Detector A Detector B Detector C Detector E Detector F Field data: * Data for Detector D were not valid due to detector failure.

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From page 584...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 584 SwashSim: TransModeler:

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From page 585...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 585 Site 11: Speed distribution in Westbound Direction (No passing lane) Vehicles are traveling in this direction (WB)

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From page 586...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 586 Regular lane Detector A Detector B Detector C Detector E Detector F Field data: * Data for Detector D were not valid due to detector failure.

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From page 587...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 587 Vehicles are traveling in this direction (EB)

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From page 588...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 588 Regular lane Detector A Detector B Detector C Detector E Detector F Field data: * Data for Detector D were not valid due to detector failure.

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From page 589...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 589 SwashSim: TransModeler: Site 11: Headway distribution in Westbound Direction (No passing lane)

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From page 590...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 590 Vehicles are traveling in this direction (WB)

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From page 591...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 591 Regular lane Detector A Detector B Detector C Detector E Detector F Field data: * Data for Detector D were not valid due to detector failure.

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From page 592...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 592 Vehicles are traveling in this direction (SB)

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From page 593...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 593 Detector A Detector B Detector C Detector D Detector E Detector F Field data: SwashSim: * See Calibration Note 1 TransModeler: Passing lane: Detector B Detector C Detector D Field data:

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From page 594...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 594 SwashSim: TransModeler:

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From page 595...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 595 Site 13: Speed distribution in Northbound Direction Vehicles are traveling in this direction (NB)

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From page 596...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 596 Detector A Detector B Detector C Detector D Detector E Detector F Field data: * See calibration note 2 SwashSim: TransModeler: Site 13: Headway distribution in Southbound Direction

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From page 597...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 597 Vehicles are traveling in this direction (SB)

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From page 598...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 598 Detector A Detector B Detector C Detector D Detector E Detector F Field data: SwashSim: * See calibration note 1 TransModeler: Passing lane: Detector B Detector C Detector D Field data:

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From page 599...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 599 SwashSim: * See calibration note 1 TransModeler:

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From page 600...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 600 Site 13: Headway distribution in Northbound Direction Vehicles are traveling in this direction (NB)

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From page 601...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 601 Detector A Detector B Detector C Detector D Detector E Detector F Field data: SwashSim: TransModeler: Site 17: Speed distribution in Southbound Direction

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From page 602...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 602 Vehicles are traveling in this direction (SB)

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From page 603...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 603 Detector A Detector B Detector C Detector D Detector E Detector F Field data: * Calibration Note 3 SwashSim: TransModeler: Detector G Detector H Detector I Detector J Detector K Detector L Field data:

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From page 604...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 604 SwashSim: TransModeler: Passing lane: Detector B Detector C Detector D Detector E Field data:

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From page 605...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 605 SwashSim: TransModeler:

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From page 606...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 606 Site 17: Speed distribution in Northbound Direction Vehicles are traveling in this direction (NB)

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From page 607...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 607 Detector A Detector B Detector C Detector D Detector E Detector F Field data: * Calibration Note 3 SwashSim: *

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From page 608...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 608 SwashSim: TransModeler: Passing lane: Detector D Detector E Field data:

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From page 609...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 609 SwashSim: * See Calibration Note 1 TransModeler:

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From page 610...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 610 Site 17: Headway distribution in Southbound Direction Vehicles are traveling in this direction (SB)

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From page 611...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 611 Detector A Detector B Detector C Detector D Detector E Detector F Field data: SwashSim: TransModeler: Detector G Detector H Detector I Detector J Detector K Detector L Field data:

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From page 612...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 612 SwashSim: TransModeler: Passing lane: Detector B Detector C Detector D Detector E Field data:

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From page 613...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 613 SwashSim: TransModeler:

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From page 614...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 614 Site 17: Headway distribution in Northbound Direction Vehicles are traveling in this direction (NB)

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From page 615...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 615 Detector A Detector B Detector C Detector D Detector E Detector F Field data: SwashSim: * See Calibration Note 1 TransModeler:

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From page 616...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 616 Detector G Detector H Detector I Detector J Detector K Detector L Field data: SwashSim: TransModeler:

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From page 617...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 617 Passing lane: Detector D Detector E Field data: SwashSim: * See Calibration Note 1 TransModeler:

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From page 618...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 618

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From page 619...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 619 Site 1: Speed distribution in Northbound Direction Vehicles are traveling in this direction (NB)

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From page 620...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 620 Detector A Detector B Detector C Detector D Detector E Detector F Field data: SwashSim: TransModeler: Site 1: Speed distribution in Southbound Direction

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From page 621...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 621 Vehicles are traveling in this direction (SB)

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From page 622...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 622 Detector A Detector B Detector C Detector D Detector E Detector F Field data: SwashSim: TransModeler: Site 1: Headway distribution in Northbound Direction

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From page 623...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 623 Vehicles are traveling in this direction (NB)

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From page 624...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 624 Detector A Detector B Detector C Detector D Detector E Detector F Field data: SwashSim: TransModeler: Site 1: Headway distribution in Southbound Direction

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From page 625...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 625 Vehicles are traveling in this direction (SB)

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From page 626...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 626 Detector A Detector B Detector C Detector D Detector E Detector F Field data: SwashSim: TransModeler: Site 4: Speed distribution in Northbound Direction

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From page 627...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 627 Vehicles are traveling in this direction (NB)

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From page 628...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 628 Detector A Detector B Detector C Detector D Detector E Field data: SwashSim: TransModeler: Site 4: Speed distribution in Southbound Direction

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From page 629...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 629 Vehicles are traveling in this direction (SB)

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From page 630...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 630 Detector A Detector B Detector C Detector D Detector E Field data: SwashSim: TransModeler: Site 4: Headway distribution in Northbound Direction

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From page 631...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 631 Vehicles are traveling in this direction (NB)

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From page 632...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 632 Detector A Detector B Detector C Detector D Detector E Field data: SwashSim: TransModeler: Site 4: Headway distribution in Southbound Direction

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From page 633...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 633 Vehicles are traveling in this direction (SB)

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From page 634...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 634 Detector A Detector B Detector C Detector D Detector E Field data: SwashSim: TransModeler: Site 7: Speed distribution in Northbound Direction

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From page 635...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 635 Vehicles are traveling in this direction (NB)

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From page 636...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 636 Detector A Detector B Detector C Detector D Detector E Field data: SwashSim: TransModeler: Site 7: Speed distribution in Southbound Direction

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From page 637...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 637 Vehicles are traveling in this direction (SB)

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From page 638...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 638 Detector A Detector B Detector C Detector D Detector E Field data: SwashSim: TransModeler: Site 7: Headway distribution in Northbound Direction

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From page 639...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 639 Vehicles are traveling in this direction (NB)

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From page 640...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 640 Detector A Detector B Detector C Detector D Detector E Field data: SwashSim: TransModeler: Site 7: Headway distribution in Southbound Direction

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From page 641...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 641 Vehicles are traveling in this direction (SB)

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From page 642...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 642 Detector A Detector B Detector C Detector D Detector E Field data: SwashSim: TransModeler: Montana Site 73: Speed and Headway distribution in both directions

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From page 643...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 643

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From page 644...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 644 Detector A (EB) Detector A (WB)

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From page 645...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 645

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From page 646...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 646 Detector A (WB) Detector A (EB)

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From page 647...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 647

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From page 648...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 648 Detector A (NB) Detector A (SB)

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From page 649...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 649

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From page 650...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 650 Detector A (NB) Detector A (SB)

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From page 651...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 651 Calibration Notes: Note 1: (Oregon Site 13 Detector D, Southbound; Oregon Site 17 Detector D, Northbound) There is a significant difference between the field and SwashSim detector measurements at the end point of the passing lane segment because of the respective geometric configurations.

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From page 652...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 652 Note 2: (Oregon Site 13 Detector E, Northbound) Some detectors failed to collect data in the field, which led to a null speed/headway distribution, or there is a large difference in volume between two detectors within a short distance.

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From page 653...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 653 0 10 20 30 40 50 60 0 200 400 600 800 1000 1200 1400 1600 1800 Av er ag e Sp ee d (m i/h )

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From page 654...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 654 0 10 20 30 40 50 60 0 200 400 600 800 1000 1200 1400 1600 1800 Av er ag e Sp ee d (m i/h )

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From page 655...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 655 0 10 20 30 40 50 60 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 Av er ag e Sp ee d (m i/h )

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From page 656...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 656 0 10 20 30 40 50 60 0 200 400 600 800 1000 1200 1400 1600 1800 Av er ag e Sp ee d (m i/h )

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From page 657...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 657 0 10 20 30 40 50 60 0 200 400 600 800 1000 1200 1400 1600 1800 Av er ag e Sp ee d (m i/h )

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From page 658...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 658 0 10 20 30 40 50 60 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 Av er ag e Sp ee d (m i/h )

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From page 659...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 659 0 10 20 30 40 50 60 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 Av er ag e Sp ee d (m i/h )

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From page 660...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 660 0 10 20 30 40 50 60 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 Av er ag e Sp ee d (m i/h )

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From page 661...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 661 0 10 20 30 40 50 60 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 Av er ag e Sp ee d (m i/h )

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From page 662...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 662 0 10 20 30 40 50 60 0 200 400 600 800 1000 1200 1400 1600 1800 Av er ag e Sp ee d (m i/h )

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From page 663...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 663 0 10 20 30 40 50 60 0 200 400 600 800 1000 1200 1400 1600 1800 Av er ag e Sp ee d (m i/h )

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From page 664...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 664 0 10 20 30 40 50 60 0 200 400 600 800 1000 1200 1400 1600 1800 Av er ag e Sp ee d (m i/h )

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From page 665...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 665 0 10 20 30 40 50 60 0 200 400 600 800 1000 1200 1400 1600 1800 Av er ag e Sp ee d (m i/h )

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From page 666...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 666 0 10 20 30 40 50 60 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 Av er ag e Sp ee d (m i/h )

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From page 667...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 667 0 10 20 30 40 50 60 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 Av er ag e Sp ee d (m i/h )

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From page 668...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 668 0 10 20 30 40 50 60 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 Av er ag e Sp ee d (m i/h )

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From page 669...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 669 0 10 20 30 40 50 60 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 Av er ag e Sp ee d (m i/h )

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From page 670...

... NCHRP 17-65 Improved Analysis of Two-Lane Highway Capacity and Operational Performance Final Report 670 0 10 20 30 40 50 60 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 Av er ag e Sp ee d (m i/h )

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Key Terms

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