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Chapter 4. Results of Smoothness Data Analysis
Pages 41-162

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From page 41... ... While these findings are indications of He beneficial effects of initial pavement smoothness on the ride quality of He pavement, they are based on Innited data over a Ignited range of roughness values. Under this project, pavement projects from a wide range of data sources were used to further evaluate the effect of initial pavement smoothness on the future smoothness of the pavement. Read the entire page →
From page 42... ... 30 40 Figure 17. Initial pavement smoothness versus average annual maintenance costs Janoff 1991~. Read the entire page →
From page 43... ... Roughness data from the Alabama Pavement Roughness Study were also included with the SHA data for use as the centerpiece of the analysis. Roughness data from the various road tests and pavement performance studies were generally much less revealing than the State-furIiished data. Read the entire page →
From page 44... ... Sources of Data for Project Analysis Data Base Past Road Tests AASHO Road Test The AASHO Road Test represents one of the most comprehensive studies of pavement performance that has ever been conducted. Over 800 AC and PCC pavement study sections were constructed and evaluated from 1958 to 1960. Read the entire page →
From page 45... ... With several sources, however, such Initial data were not available, either because the construction records containing the test results had been discarded or because the ~rutial pavement smoothness was not being monitored by the SHA at that time. In those instances, pavement management smoothness measurements made within 2 to 3 years of construction were used as Initial smoothness values. Read the entire page →
From page 46... ... Mays Meter Mays Meter South Dakota type Profiler South Dakota type Profiler RI (Mays Meter) GM Profilometer South Dakota type Profiler California Profilograph PCA Roadmeter PSI (Mays Meter) Read the entire page →
From page 47... ... 2. The performance curves of two pavements constructed to different initial smoothness levels but of otherwise similar design roughly "parallel" each other, with the rougher section perhaps deteriorating more rapidly due to greater dynamic loadings and/or greater variability in construction. Read the entire page →
From page 48... ... As discussed previously, pavement projects were solicited from SHAs containing multiple sections constructed to different Crucial smoothness values. Because the pavement design, cross section, subgracle support, traffic loadings, age, and climatic forces are approx~nately We same for each of the sections within Me project, the effect of these variables on the performance of all of Me sections is assumed to be constant and Me effect of nutial pavement smoothness can therefore be isolated. Read the entire page →
From page 49... ... was selected in order to provide an Indication of the significance of the initial smoothness variable. In many cases, nonlinear regression provided a better "fit" of the data, and these improved moclels were used in the analysis on the effect of initial pavement smoothness on pavement life (described later) Read the entire page →
From page 50... ... are also outputs of the regression analysis. The statistical significance of Me independent variables is evaluated using the p-value, which indicates the probability that the significance of the effect of the independent variable fin this case, initial pavement smoothness) Read the entire page →
From page 52... ... Four different age ranges were considered In this evaluation and are as follows: � O to 5 years All projects win roughness data available within the first 5 years of Me life of the pavement. O to 10 years All projects win roughness data available widen the first 10 years of the life of the pavement. Read the entire page →
From page 53... ... _ Alabama-BPR Roughometer, in/nu 19.79 17.02 19.59 32.18 40.06 0.05 1.98 3.87 7.54 3.91 27.01 28.38 70.32 19.13 21.72 20.48 21.39 25.10 _11.55 23.88 10.37 25.29 _19.59 60.88 31.62 25.16 12.73 4.05 7.59 -1.51 0.94 1.82 24.48 33.31 6.66 53 o~ 0-6 0-5 ~5 0-5 0-5 ~7 0-7 0-7 ~7 ~7 0-7 0-7 0-7 0-3.5 0-3.5 0-3.5 0-3.5 0-6.6 0-6.6 0-6 0-6 0~ 0-6 0-7 0-7 0-7 0-7 0-7 0-7 0-7 0-7 0-7 0-7 0-7 0.76 0.81 0.82 0.68 0.54 1.01 0.97 0.95 0.91 0.95 0.62 0.60 0.11 0.74 0.81 0.81 0.80 0.76 0.84 0.71 0.91 0.77 0.82 0.38 0.65 0.73 0.87 0.96 0.92 1.00 0.99 0.98 0.73 0.63 0.94 2.61 2.48 0.16 -1.60 3.77 3.57 3.69 4.42 3.75 3.21 3.05 3.12 1.29 3.30 2.12 2.02 3.34 3.32 2.24 2.38 2.96 1.68 2.24 . Read the entire page →
From page 54... ... PCC AC 1961 13 961_ 13 1961 13 1962 6 _ 1962 6 Anzona-Mays Meter, in/nu TPC 1974 1 5 1 0-5 - 1 5 1 0-10 _ TPC 1974 5 0-15 1974 5 0-19 TP JPC 1976 11 0-4 ~1976 _ 11 0-8 TPC 1976 11 0-12 IPC 1976 11 0-17 1972 12 0-4 TP IPC 1972 12 0-8 IPC 1972 12 0-14 TPC ~ - 1974~ _ 4 0-5 TPC 1974 4 0-10 {PC 1974 4 0-15 TPC 1974 4 0-19 . Read the entire page →
From page 55... ... . Proj ect ID Pavement Type 1 1 I-15 NB Mo eve Co. Read the entire page →
From page 56... ... Year 1981 1981 1981 1981 1987 1987 1981 1981 1981 1981 1980 1980 1985 1985 1987 1987 1986 1983 1980 1980 1987 Age Range, year 0-9 ~13 0-9 ~13 ~5 0-7 ~5 0-11 0-5 0-11 ~5 _ 0-11 ~5 ~9 ~5 ~7 0-8 0~ 04 ~7 ~5 an (ins) 21.97 24.14 15.36 5.40 -1.28 -10.17 _ -1.24 32.47 9.05 11.80 13.04 20.27 7.72 13.37 17.28 25.44 18.76 2.77 13.68 16.52 0.33 Illinois-BPR Roughometer, in/ml 1972 lg72 1971 1971 1969 1975 1977 1971 1971 1973 197B 1978 1977 1977 1976 56 7.23 8.73 29.47 25.24 19.27 37.76 51.65 -21.47 -5.52 50.34 38.70 58.49 33.00 5.55 4.29 alof sit 0.33 0.30 0.43 0.78 .02 .30 1.29 -0.0 0.66 0.53 0.29 0.16 0.76 0.56 0.22 -0.08 0.41 1.06 0.27 0.21 0.96 0.83 0.77 0.62 0.62 0.61 0.34 0.20 1.22 _1 O_ o.Os 0.46 0.28 0.11 1.00 0.51 a2 of Time -0.10 -0.61 -0.19 -0.07 .5 1.31 -0.69 -0.54 -0.55 o.O9 3.24 1.36 -0.26 l -0.57 0.92 l 0.21 -0.52 l 1.42 2.08 1.09 0.68 2.51 2.85 2.30 2.47 2.54 4.48 s.32 2.02 2.29 l 3.82 3.53 2.87 4.80 5.12 4.49 R2 . Read the entire page →
From page 57... ... . Proj ect ID Pavement Type I-55 SB Livingston Co. Read the entire page →
From page 58... ... 1982 4 1982 4 . Age Range, year 0-8 0-4 0-8 0~ 0-8 0~ 0-8 0-12 0-4 __0-8 . Read the entire page →
From page 59... ... 1991 1989 No. of Sections 8 7 _ 4 Age Range, year = ~ 0-5 0~ 0-5 an (ins) Read the entire page →
From page 60... ... (2) Wisconsin-Mays Meter converted to PSI AC 1978 1 9 10-6 1 -1.84 AC 1978 0-12 -3.06 AC 1978 9 ~16 -2.70 AC 1978 0-6 7.82 AC 1978 4 0-12 10.49 _ AC 1978 0-16 12.12 _ _ . Read the entire page →
From page 61... ... GOiX & DUnn CO. -_ US 18 WB IOWa & Dane CO Pavement Type JPC w/o Dwls JPC W/O DWlS TPC W/O DW1S TPC W/O DWlS IPC W/O DWlS ~C w/o Dwls JPC W/O DWlS JPC W/O DW1S JPC W/O DWlS TPC W/O DWlS TPC W/O DWlS . Read the entire page →
From page 62... ... Proj ect . ID _ US 8 EB & WB Marinette Co. Read the entire page →
From page 63... ... Table 10. Effect of in~tial smoothness on future smoothness for various SHA Projects (continued) Read the entire page →
From page 64... ... The information presented in table 10 represents a significant amount of data. To aid In the interpretation of this data, the results of table 10 have been summarized In table At, which indicates by State and by pavement type the percentage of projects in which initial pavement smoothness had a significant effect on the future smoothness of Me pavement. Read the entire page →
From page 65... ... Tables 12 through 15 break out the percentage of projects showing the significance of initial pavement smoothness by age range. Table 12 provides the results for projects in the O-to-5 age range, table 13 provides the results for projects in the O-to-1O age range, table 14 provides We results for projects in Me 0-to-15 age range, and table 15 provides the results for the projects in Me 0-to-greater-than-15 age range. Read the entire page →
From page 66... ... 1~1 Overlays Figure 25. Percentage of projects showing significance of initial pavement smoothness (by State and type of construction) Read the entire page →
From page 67... ... Overall percentage of projects showing significance of initial pavement smoothness (by type of construction) Read the entire page →
From page 68... ... Summary of significance of Initial pavement smoothness, O-to-IO age range. Read the entire page →
From page 69... ... Sununary of significance of initial pavement smoothness, O-to-greater-than-15 age range. Read the entire page →
From page 70... ... AC overlay projects, on the other hand, show fairly constant values over the different age ranges, although no projects are available for the O-to-greater-than-15 age range category. Read the entire page →
From page 71... ... Overlays Figure 29. Percentage of projects showing significance of initial pavement smoothness (by age range and type of construction) Read the entire page →
From page 72... ... Average initial smoothness regression coefficient Gaul by pavement type and age range. l l Av Rage Initial Smoothness Regression Coefficient' a I Age l \| Range AC PCC AC/AC AC/PCC New \| Pavements Pavements \| Pavements Pavements \|\|Constructic nl Overlays \|\| 0-5 1 1.02 0.87 1 0.69 0~7411 0~91 1 0 71 1~ . Read the entire page →
From page 73... ... Average a1 values by pavement type for all projects and age ranges. All Projects, All Age Ranges ~ 0.8 ._ ._ = g 0.6 c' ~ 0.4 an 0.2 o 0.82 New Constr. Read the entire page →
From page 74... ... However, the average al value then begins to drop off for AC pavements outside of the O-to-5 age range, showing levels of 0.75, 0.66, and 0.40 for the O-to-IO, O-to-15, and O-to-greater-than-15 age range categories, respectively. This suggests that initial pavement smoothness does not have as significant effect for the older AC pavements. Read the entire page →
From page 75... ... Considering all age ranges, initial pavement smoothness was shown to have a significant effect in 80 percent of both new AC construction projects and new PCC pavement construction projects. AC overlay projects show a somewhat lesser percentage (70 percent) Read the entire page →
From page 76... ... Breakout of overall significance by pavement type. Read the entire page →
From page 77... ... ~ ~ ~ ~ -; ~ ~ ~ it{ x ~ , , _ _ ::::::~::^i;::::: :.~:::_ :' 1 ~s~ . Read the entire page →
From page 78... ... for - - ~ 1 w ~, ~1 - -t ~� t-t / ~ ~ ~ 78 r ~ Y .0 ~ I ~ ~ 1 O A) Read the entire page →
From page 79... ... The results of those evaluations are presented below. AASHO Road Test Performance data from the AASHO Road Test are available for both AC and PCC pavements and are provided In units of present serviceability index (PSI) Read the entire page →
From page 80... ... , then the null hypothesis is rejected and the alternate hypothesis is accepted, meaning that it can be inferred with 90 percent confidence that the initially smoother sections maintain a higher smoothness level than the initially rougher sections. The t-test results for the AC pavement sections and the PCC pavement sections are presented In table 17 and 18, respectively. Read the entire page →
From page 81... ... Table 17. Summary of the t-test results for AASHO data, AC pavement sections. Read the entire page →
From page 82... ... Table 18. Summary of the t-test results for AASHO data, PCC pavement sections. Read the entire page →
From page 83... ... However, the structural number (SN) of the AC pavements and the slab thickness of the PCC pavements were introduced as independent variables in the regression analysis to account for differences in the design between pavement sections. Read the entire page →
From page 84... ... O- 1 1 1 - 1 1 1 0.00 5.00 10.00 15.00 20.00 25.00 30.00 Age, years Figure 36e Historical roughness plots for LTPP GPS-5 experiment (Kohn et al. Read the entire page →
From page 85... ... cited roughness as a primary variable used In their pavement management system for establishing Me worth of candidate projects (Zimmerman 1995~. Thus, many highway agencies believe that pavement smoothness is a primary factor considered by the highway users as representing the quality of the highway. Read the entire page →
From page 86... ... , they did provide a sampling of the relationship between initial PSI and pavement life. The pertinent data included pavement type, construction and rehabilitation dates, pavement distress data, and initial and final PS] Read the entire page →
From page 87... ... aO' al, as, a3 = Regression coefficients. Si = Initial pavement smoothness. Read the entire page →
From page 88... ... be, b2, be, b4 = Exponent coefficients for initial smoothness, time, and initial smoo~ness-time Interaction variables. Si = Initial pavement smoothness. Read the entire page →
From page 89... ... for use in each roughness model such that the tune to reach the trigger roughness value could be computed for various ~rutial smoothness values. This approach is basec! Read the entire page →
From page 90... ... These plots were generated over the available initial smoothness data range only, and upper life limits of 50 years for asphalt pavements and 75 years for concrete pavements were selected corresponding to baselines or target, nutial smoothness levels of 5 in/ml (0.08 m/km) Read the entire page →
From page 91... ... city ~ ~ m. Read the entire page →
From page 92... ... Step 2: Use Model to Project Pavement Life 1 8 0 1 6 0 ._ ~ 140 3 ~, 120 ~D ~ 100 =~ 8( ~o 60 ~n ,St :.c Section 1 D ata a Section 2 D ata ~Section 3 D ata 0 Section 4 D ata Best-Fit M odel at Initial w 10 in/m i Best-Fit M odel at Initial = 20 in/m i Best-Fit M odel at Initial = 30 in/m i -- - Best-Fit M odel at Initial ~ 50 in/m i 30 35 40 _ ~ _ _ _ _ Trigger Value ~ 175 in/m ~ ~ 1~-= v ~ ~ ~ ~ ~c Section 1 D ata 0 Section 2 D ata Section 3 D ata ~ Section 4 Data -- -- - Best-Fit M odel at Initial 1 0 in / m i Best-Fit M odel at Initial ~ 20 in/ml Best-Fit M odel at Initial ~ 30 in/m i -- -Best-Fit M odel at Initial :~ 50 in/ml cazo ;~d lrears 29 Year ~-., 0 ~i~ ~ ~ ~ ~=' ~ 0 5 10 15 20 25 A ge (years) 30 35 40 Step 3: Plot Pavement Lives for Range of Initial Smoothness Values and Detemune Relationship 40 T 35 L 30 4, 25 ;^ 20 u ~, 15 0 5 10 15 20 25 30 35 In itia I M ay s R id e N u m b er (in /m i) Read the entire page →
From page 93... ... Therefore, a linear regression was fit through the predicted life versus ~rutial smootlu~ess data for each pavement type within each State in order to quantify the general predicted life versus initial smoothness trend. The use of a linear trenc! Read the entire page →
From page 94... ... The resulting smoothness-life trends for the various pavement projects included in the study are provided in figures D-l through D-35 of appendix D The project trends have been grouped according to pavement family (i.e., State and pavement type) Read the entire page →
From page 95... ... . ~ Me sensitivity analysis carried out here, the target initial smoothness levels for each pavement family were established using the approximate values given In table 21 corresponding to PI values of 7 in/ml (0.~! Read the entire page →
From page 96... ... Pavement Family Smoothness-Life Prediction Equation Life = -0.187BPRAL + 34.994 Life - -0.247BPRAL + 43.025 Life = -0.175MRNAz + 24.883 _, Alabama PCC Alabama AC Arizona JPC Arizona AC Arizona AC/JPC Arizona AC/AC Georgia JPC Life = -0.229MRNAz + 44.374 Life = -0.098MRNAz + 14.385 Life = 0.138MRNAz + 26.883 Life = -0.454MRNGA + 30.175 Life = -0.260MR>JGA + 20.423 Georgia AC Georgia AC/JPC Georgia AC/AC Life = -0.413MRNGA + 30.351 Life = -0.557MRNGA + 25.714 Illinois CRC Illinois AC/CRC Illinois AC/JRC Kentucky PCC Interstate Kentucky AC Interstate Kentucky AC/PCC Interstate Kentucky AC/AC Interstate Kentucky AC/PCC Parkway Life = -0.180IRI~L + 32.009 Life =-0.079IRI~ + 14.943 Life = -0.080IRIIL + 14.196 Life = 12.116RIK,, - 23.429 Life = 6.650RIK~,- 14.336 Life = 11.390RIKy~ 22.304 Life = 10~989RIKy- 18.821 Life = 13.583RIK,'- 37.608 Kentucky AC/AC Parkvvay Michigan JRC Michigan AC Michigan AC/PCC Minnesota PCC Minnesota AC Minnesota AC/AC South Dakota PCC Washington PCC Washington AC Washington AC/AC Wisconsin CRC Wisconsin JPC (w/o dowels) Wisconsin JRC Wisconsin AC Wisconsin AC on Rigid Base Wisconsin AC on Flexible Base Life = 4~647RIKy - 3.535 Life =-0.153IRIMI + 30.767 Life = -0.040IRIMI + 17.147 Life = -0.123IRIMI + 20.213 Life =-0.051IRIMN + 7.520 Life = -0.113RIMN + 18.060 Life = -0.198IRIMN + 31.891 Life = -1.849PIsD + 49.372 Life =-0.105PCAWA + 36.638 Life = -0.065PCAWA + 28.006 Life = ~.030PCAWA + 28.254 Life = 9.567PSIW, - 27.410 Life = 6.912PSIWl -19.675 Life = 7.220PSIW, - 23.869 Life = 7.896PSIW' -17.293 Life = 5.474PSIW~ -13.725 Life = 5.042PSIw~ -11.207 96 Read the entire page →
From page 97... ... This table lists, for each pavement family, the target initial smoothness level, the sensitivity ratio (i.e., the rate of percentage change in life divided by the percentage change in roughness) , and the percentage increases in life corresponding to smoothness increases (from the target level) Read the entire page →
From page 98... ... Pavement Family Alabama PCC Alabama AC Arizona JPC Arizona AC Arizona AC/JPC Arizona ACiAC Georgia JPC Georgia AC Georgia AC/JPC Georgia ACiAC Illinois CRC Illinois AC/CRC Illinois AC/JRC Kentucky PCC Interstate Kentucky AC Interstate Kentucky AC/PCC Interstate Kentucky AC/AC Interstate Kentucky AC/PCC Parkway Kentucky AC/AC Parkway Michigan JRC Michigan AC Michigan AC/PCC Minnesota PCC Minnesota AC Minnesota AC/AC South Dakota PCC Washington PCC Washington AC Washington ACiAC Wisconsin CRC Wisconsin JPC (w/o dowels) Wisconsin JRC Wisconsin AC Wisconsin AC on Rigid Base Wi~ce~n.~in ACT on Flexible Bane 1 in/ml = 0.0158 m/km 1 mi = 1.61 km Target Initial Smoothness Level BPRAL = 100 in/ml BPRAL = 80 in/ml MRNAZ = 60 in/ml MRNAZ = 50 in/ml MRNAZ = 50 in/ml MRNAZ = 50 in/ml MRNGA - 25 injmi MRNGA = 20 in/ml MRNGA = 20 in/ml MRNGA = 20 in/ml 8IlL = 55 in/ml IRIS = 50 in/ml IRIIL = 50 in/ml - RIKy = 4.0 RIKY = 4.1 RIKY = 4~1 RIKY = 4~1 RIKY = 4~1 RIM = 4.1 IRIM, = 55 in/ml IRIS = 50 in/ml IRIM' = 50 in/ml IRIMN = 55 in/ml IRIMN = 5.0 in/ml IRISH = 50 in/ml PIED = 7.0 in/ml PCAWA= 100 cts/mi PCAWA = 60 cts/mi PCAWA = 60 cts/mi PSIW~ = 4.0 PSIWl = 4.0 Sensitivity Ratio (%^Life/%^Roughness) Read the entire page →
From page 99... ... At higher ranges, the curves become more consistent in showing Cat initially smoother pavements provide additional life. This trend is borne out for all pavement types-PCC, AC, AC/AC, and AC/PCC. Read the entire page →
From page 100... ... Pavement failure curves for PCC interstate pavements in Kentucky (all traffic levels) Read the entire page →
From page 101... ... Pavement failure curves for AC interstate pavements in Kentucky (all tTaffic levels) Read the entire page →
From page 102... ... Pavement failure curves for AC/AC interstate pavements in Kentucky (all traffic levels) Read the entire page →
From page 103... ... Pavement failure curves for AC/PCC interstate pavements in Kentucky (all traffic levels) Read the entire page →
From page 104... ... First, although Kentucky does have AC overlays of PCC pavements (AC/PCC) on their parkway system, failure curves for this pavement group were not constructed due to the very small percentage (less than 2 percent overall) Read the entire page →
From page 105... ... These six included the three Kentucky AC interstate trends-all of which were close to zero-and three individual Kentucky group trends corresponding to 10 percent projects overlaid. Although the slopes (change in life/change in serviceability of the linear regression curves vary by pavement group, the plots largely confirm a direct positive relationship between pavement life and initial serviceability for the serviceability ranges defined by Me failure curves. Read the entire page →
From page 106... ... Interestingly, the pavement life corresponding to the target Initial smoothness level and 25 percent projects overlaid varied by pavement group. This gives an indication of how service life is also dependent on other factors, such as pavement type and functional classification (traffic) Read the entire page →
From page 107... ... Summary and Significance of Results The results of the evaluation strongly indicate that crucial pavement smoothness has a significant effect on pavement life. Using both roughness mode! Read the entire page →
From page 108... ... Based on the questionnaire survey responses, 60 percent of He highway agencies employing a smoothness specification for AC pavements believe that the specification has resulted in increased initial pavement smoothness, while 72 percent of the highway agencies employing a smoothness specification for PCC pavements believe that the specification has resulted in increased ~rutial pavement smoothness. This section investigates the effectiveness of these smoothness specifications in providing a smooth pavement surface. Read the entire page →
From page 109... ... . In 1981, Georgia switched from the PCA roadmeter to the Mays Meter for pavement smoothness testing of both pavement types. Read the entire page →
From page 110... ... Furthermore, a t-test was conducted to examine the effect of Me specification implementation on the mean value of the crucial smoothness values. Finally, graphical plots of pre- and post-specification smoothness distributions were generated to illustrate the effect of smoothness specifications on the resulting pavement smoothness. Read the entire page →
From page 111... ... Although these plots contain a few peaks, the overall trend for all pavement types is a general reduction in Me average initial roughness value. Table 26 summarizes the reductions for each pavement type. Read the entire page →
From page 112... ... systems. Figure 55 illustrates the standard deviation of the initial roughness values for each pavement type. Read the entire page →
From page 113... ... Coefficient of variation values of Crucial pavement smoothness for Towa pavements. Read the entire page →
From page 114... ... 1983~. In 1979, a trailer-mounted Mays Meter was purchased and by January I, 1981, Me Mays Meter system was used exclusively for controlling Axial pavement smoothness. Read the entire page →
From page 115... ... For all pavement types, a general reduction in initial pavement roughness is observed over that period. Figure 58 shows the mean roughness trends for pavements constructed during the 198Os and early 199Os under the Mays Meter specification. Read the entire page →
From page 116... ... Summary of reductions in Georgia mean project crucial roughness values over time. l \| 1981 Smoothness, \| 1995 Smoothness, \| Percent Change j Pavement Type I in/ml I in/ml I in Smoothness I PCC 1 65 1 33 1 4 AC Overlay 1 35 1 25 1 29 AC 1 27 ~24 1 ~n/mi = 0.0158 m/km 116 Read the entire page →
From page 117... ... Standard deviation values of Crucial pavement smoothness for Georgia pavements. � New AC - ~ - New PCC AC overlay The COV for the Georgia pavements is plotted in figure 60. Read the entire page →
From page 118... ... Coefficient of variation values of initial pavement smoothness for Georgia pavements. Table 28. Read the entire page →
From page 119... ... Comparison of initial pavement smoothness distributions before and after implementation of smoothness specification (Georgia AC overlay projects) Read the entire page →
From page 120... ... shows a definite reduction in initial roughness, although it increases slightly the next 2 years before decreasing again. In addition, the standard deviation of the initial pavement roughness is observed to slightly decrease over tune. Read the entire page →
From page 121... ... Coefficient of variation values of initial pavement smoothness for Ill~nois CRCP. Table 29. Read the entire page →
From page 122... ... Comparison of ~rutial pavement smoothness distributions before and after implementation of smoothness specification Lois CRCP projects) Read the entire page →
From page 123... ... Mean and standard deviation of initial PST over time for Wisconsin JPC pavements. Read the entire page →
From page 124... ... Mean and standard deviation of Crucial PS] over time for Wisconsin CRC pavements. Read the entire page →
From page 125... ... For each pavement type, the mean nutial PSI for the projects built after the Implementation of Me specification is significantly higher than that of the projects constructed before the ~rnplementation of the specification. The standard deviation of We Crucial PST of the projects under specification decreases significantly also. Read the entire page →
From page 126... ... Comparison of initial pavement smoothness distributions before and after implementation of smoothness specification (Wisconsin JPCP projects) Read the entire page →
From page 127... ... Comparison of initial pavement smoothness distributions before and after implementation of smoothness specification (Wisconsin CRCP projects) Read the entire page →
From page 128... ... Summary Four SHAs employing initial smoothness specifications have furnished data allowing for an investigation of the effect of Me smoothness specification on initial pavement smoothness. The data from all four States indicate that smoothness specifications have been effective in obtaining pavements that are significantly smoother Man those constructed prior to the Implementation of the specification. Read the entire page →
From page 129... ... Finally, it also appears that it takes a few years for contractors to become acquainted with smoothness specifications. After the implementation of a specification, the Initial roughness generally decreases and continues to decrease as the contractor becomes more comfortable with the specification and more cognizant of items that can be done to increase the resulting pavement smoothness. Read the entire page →
From page 130... ... Conceptual relationship between initial pavement smoothness and total life-cycle cost. Read the entire page →
From page 131... ... The converted future costs can be combined with the initial construction cost to give a total PW cost over the specified analysis period. If desired, the PW cost can be converted to an EUAC annual cost over the specified analysis period using engineering economics relationships and a selected discount rate. Read the entire page →
From page 132... ... In a 1993 AASHTO LCCA survey, fewer than half the States indicated including user costs the LCCA, with a primary concern being He difficulty in estimating the value of delay (FHWA 1994a) Read the entire page →
From page 133... ... A ceiling limit on this extra cost might be the cost of completely diamond grinding a PCC pavement or milling and overlaying an AC pavement to try to achieve a perfectly smooth surface. Although the cost of constructing a pavement smoother is greater, the added pavement life associated with increased smoothness tends to offset to a certain point the additional construction cost, such that the total life-cycle cost is lower. Read the entire page →
From page 134... ... Another part of this concern is based on whether ~ncentive/disincentive provisions for pavement smoothness are an appropriate and cost-effective proposition. The results of the contractor survey presented in appendix A suggest that the overall construction cost, including the bid price and incentive/disincentive payment, is affected lithe by Me nutial smoothness level for most nominal levels of smoothness. Read the entire page →
From page 135... ... for a range of initial smoothness levels can be Inputted Into the following pay factor formula to generate He theoretical pay factors over that range of smoothness levels: PFaC = [BPa,d + (Lccad -- L`CCac) ~/BPad where: PFac = Pay factor for as-constructed smoothness level. Read the entire page →
From page 136... ... However, it is important that We full-pay smoothness levels (pay factor equal to I.0) of both pay factor curves coincide. Read the entire page →
From page 137... ... The second type of smoothness-life relationship used for States 3 and 5 was that type generated from the pavement failure analyses. The linear trend equations associated with 25 percent projects overlaid were used directly in the LCCA, resulting in an array of life-cycle costs for different crucial smoothness levels. Read the entire page →
From page 138... ... LCCA ~Pavement Type Input ~PCC (IO-in) Read the entire page →
From page 139... ... 50 ~ 45 5 40 35 o ~ 30 ._ �4 25 ._ ~ 20d ._ ~ 15 o ~ 10 ~ en, 5 O Mean Regression Equation: y = -3.2667x + 16.333 o California profilograph (0.2-in blanking band) PI, in/ml - Contractor 1 ~ Contractor 2 - - ~ - Contractor 3 ) Read the entire page →
From page 140... ... The most cost-effective, or optimum, smoothness levels In these plots are the points where the total life-cycle costs are minimum. In most cases, these 250,000 Optimum level = 0 in/ml 200,000 .E AD a u 100,000 I P" 0 25 50 75 100 125 Initial Roughness (MRN) Read the entire page →
From page 141... ... Plot of lif~cycle costs versus initial serviceability for the State 3 AC/AC interstate pavement family. Optimum Level = 4.55 . Read the entire page →
From page 142... ... . This range is consistent with the target smoothness levels that were used in the LCCA: 5 in/ml (0.08 m/km) Read the entire page →
From page 143... ... roughness model analysis (2) pavement failure analysis I I Il I Cost-Effective Smoothness Range State Index Range Optimum Level Optimum Level for for low ASC moderate ASC (ASC 11 - a) Read the entire page →
From page 144... ... range, with application of appropriate incentives and disincentives to help secure initial pavement smoothness In the optimum smoothness range. Further discussion of this type of action is provided ~ the following section. Read the entire page →
From page 145... ... Instead of using the LCCad value corresponding to Me full-pay smoothness level of a given specification, the LCC values corresponding to PI values equal to 3 and 5 ~n/mi (0.05 and 0.08 m/km) for AC and PCC pavements, respectively, were used. Read the entire page →
From page 147... ... Theoretical and actual pay adjustment curves for State 3 AC/AC interstate pavements. Read the entire page →
From page 148... ... . -Pay factor for original target smoo~ness level - - ~ - Pay factor for new target smoothness level #1 - ~-Pay factor for new target smoothness level #2 -- - ~ -- - Current pay schedule :~:1 ... Read the entire page →
From page 149... ... Pay Factor Corresponding to: Maximum Incentive ~ ~Maximum Disincentive Pavement Family Full-Pay Level IRI=0 in/mi IRI=50 in/ml it IRI=80 in/mi (PI=0 in/mi) Read the entire page →
From page 150... ... Pay Factor Corresponding to:' ~ Maximum Incentive ~ ~Maximum Disincenti~ve Pavement Family Full-Pay Level RI=5.0 (PI=O) Read the entire page →
From page 151... ... . Pay Factor Corresponding to:' . Read the entire page →
From page 152... ... At the break-even smoothness level, the cost of additional smoothness equals the incentive payment, and the resulting pay factor is 1.0. At the most profitable smoothness level, the difference between He incentive payment and the ASC is greatest, and the resulting pay factor is represented by the maximum 152 Read the entire page →
From page 153... ... However, because many people believe that user costs should be included in a comprehensive LCCA, an attempt was made in this study to include the effects of user costs as a function of initial serviceability. Although any estimate of user costs is a crude approximation, the magnitudes of the estimated costs presented in this report are believed to be representative. Read the entire page →
From page 154... ... The appropriate cost per vehicle mile is obtained from Me updated cost tables by knowing the projected pavement smoothness and identified pavement type. Yearly user costs are calculated by multiplying the appropriate cost per vehicle mile tunes the projected number of vehicles traveling on the project for a given year (365 days times the projected ADT) Read the entire page →
From page 155... ... Figure SS. Cumulative PW user costs versus time for selected PCC pavement project. Read the entire page →
From page 156... ... . Figure 90 illustrates the savings in cumulative PW user costs over time for the three different initial smoothness levels, as compared to the yearly values at the target initial smoothness level. Read the entire page →
From page 157... ... Actual yearly, PW yearly, and cumulative PW user costs for different Crucial smoothness levels ($ thousands) Read the entire page →
From page 158... ... Graph of total LCC (including user costs) Read the entire page →
From page 159... ... Nevertheless, it is strongly believed that the magnitude of savings associated with smoother levels for other projects would stay relatively uniform, such Cat Me smoothest level is always identified as Me most costeffective level. Summary This section outlined a procedure for evaluating the cost-effectiveness of initial smoothness levels and presented a detailed evaluation of several current pavement smoothness specifications using that cost-effectiveness procedure. Read the entire page →
From page 160... ... The results of the analysis of the effect of initial pavement smoothness on the future smoothness of the pavement clearly show that nutial pavement smoothness has a significant effect 160 Read the entire page →
From page 161... ... Comparison of pavement smoothness distributions before and after the implementation of a smoothness specification indicate decreased initial roughness values and decreased variability for pavements constructed under the smoothness specification. A procedure for evaluating the cost-effectiveness of initial smoothness levels was developed and presented. Read the entire page →
From page 162... ... for PCC and AC pavements, respectively, recalculated theoretical pay adjustment curves stiD showed greater maximum incentive amounts and more punitive disincentive amounts than current pay adjustment curves. The inclusion of user costs in a comprehensive LCCA has a profound effect on the determination of the most cost-effective smoothness level. Read the entire page →

From page 41...

... While these findings are indications of He beneficial effects of initial pavement smoothness on the ride quality of He pavement, they are based on Innited data over a Ignited range of roughness values. Under this project, pavement projects from a wide range of data sources were used to further evaluate the effect of initial pavement smoothness on the future smoothness of the pavement.

Chapter 4. Results of Smoothness Data Analysis Pages 41-162

Chapter 4. Results of Smoothness Data Analysis
Pages 41-162