Guide for the Analysis of Multimodal Corridor Access Management (2018) / Chapter Skim
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Pages 85-114
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From page 85... ...
85 Introduction This appendix provides guidance on applying the quantitative analysis methods that appear most often in the guide. These methods can estimate performance measures that describe how access management techniques interact with the operations or safety performance of particular travel modes.
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86 Guide for the Analysis of Multimodal Corridor Access Management • HCM6 multimodal level of service (MMLOS) methods.
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Applications Guidance for Selected Quantitative Analysis Methods 87 practical to apply by using specialized software, given the number of computations involved. A number of commercial software packages are available that perform these calculations for some or all of these intersection types.
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88 Guide for the Analysis of Multimodal Corridor Access Management stop-controlled intersections. Other input data can be defaulted, but the fewer default values that are used the greater is the chance that the end result is likely to be accurate.
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Applications Guidance for Selected Quantitative Analysis Methods 89 up to 3 mph. In most cases, the speed increase will be lower, as right-turn lanes, driveways, and unsignalized intersections between traffic signals will reduce the street length where parking is allowed.
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90 Guide for the Analysis of Multimodal Corridor Access Management Step 1. Determine the base free-flow speed.
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Applications Guidance for Selected Quantitative Analysis Methods 91 fcs = adjustment for cross-section (mph) , from Table A2 fA = adjustment for access point density (mph)
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92 Guide for the Analysis of Multimodal Corridor Access Management Step 3. Calculate the average midblock running speed.
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Applications Guidance for Selected Quantitative Analysis Methods 93 no right-turn lanes at access points, 1,000 vehicles per hour in the direction of travel, and a peak hour factor of 0.92. The average midblock running speed is calculated as follows: Step 1.
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From page 94... ...
94 Guide for the Analysis of Multimodal Corridor Access Management all-way stop-controlled intersections (Chapter 21) , and roundabouts (Chapter 22)
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Applications Guidance for Selected Quantitative Analysis Methods 95 The following section focuses on link-based evaluations and discusses relevant aspects of segment-based evaluations. All calculations can be performed by hand or readily input into a spreadsheet.
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96 Guide for the Analysis of Multimodal Corridor Access Management where ln = natural logarithm WT = total width of outside through lane, bicycle lane, parking lane, and shoulder (ft) WSW = available sidewalk width, not including landscape buffer or furnishing zone (ft)
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From page 97... ...
Applications Guidance for Selected Quantitative Analysis Methods 97 the before-and-after values of Fs are 0.71 and 0.77, respectively. Because nothing else changes that would affect PLOS, the PLOS value would go up (i.e., get worse)
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98 Guide for the Analysis of Multimodal Corridor Access Management (a)
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Applications Guidance for Selected Quantitative Analysis Methods 99 Bicycle LOS Links A number of factors influence bicycle LOS (BLOS) for a roadway link.
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100 Guide for the Analysis of Multimodal Corridor Access Management The cross-section adjustment factor Fw is generally a function of the outside travel lane width, bicycle lane and shoulder width (if present) , and parking presence and occupancy.
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Applications Guidance for Selected Quantitative Analysis Methods 101 Equations A16 through A18, adapted from Equations 18-43 through 18-45, respectively, in the HCM6 (1) , determine the motorized vehicle volume and speed adjustment factors and the pavement condition adjustment factor.
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102 Guide for the Analysis of Multimodal Corridor Access Management Segments The number of access points per mile on the right side of the road is a factor in determining BLOS at the segment level. Equations 18-46 and 18-47 in the HCM6 can determine segment BLOS.
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Applications Guidance for Selected Quantitative Analysis Methods 103 Transit LOS Transit LOS (TLOS) for a roadway link is influenced by the bus frequency on the link, passengers' perceived travel time (primarily a function of bus speeds and loading)
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104 Guide for the Analysis of Multimodal Corridor Access Management TLOS due to particular access management techniques, without having to perform the full set of calculations.
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Applications Guidance for Selected Quantitative Analysis Methods 105 Increases in average midblock motor vehicle speeds produce much smaller increases in average bus speeds, when bus stop and traffic signal delays are considered. Buses spend relatively little time per mile traveling at a street's running speed, and much more time stopping to serve passengers (including time spent decelerating and accelerating back to running speed)
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From page 106... ...
106 Guide for the Analysis of Multimodal Corridor Access Management Pedestrian and Bicycle Delay Methods in the HCM6 Pedestrian Delay Chapter 19 in the HCM6 provides Equation 19-70 (1) for estimating average pedestrian delay crossing one crosswalk at a traffic signal, assuming random pedestrian arrivals at the crosswalk: 2 (A25)
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From page 107... ...
Applications Guidance for Selected Quantitative Analysis Methods 107 Truck Level of Service Section P in Exhibit 3 of NCHRP Report 825 (2) describes the use of a truck LOS measure developed in NCFRP Report 31 (5)
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108 Guide for the Analysis of Multimodal Corridor Access Management where fLA = local adjustment factor to account for local truck driving behavior (decimal) (default = 1.00)
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Applications Guidance for Selected Quantitative Analysis Methods 109 Crash Modification Factors Crash modification factors are tools for estimating the effect of selected access management techniques on a roadway's crash rate. They can be applied directly to a known, long-term (e.g., 5 years or more)
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110 Guide for the Analysis of Multimodal Corridor Access Management Table A10 provides the model coefficients for each combination of crash type and median type. The models are only applicable to urban and suburban arterials with characteristics within the range indicated in Table A11.
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Applications Guidance for Selected Quantitative Analysis Methods 111 The predicted vehicle–pedestrian crash rate for the existing roadway is CR 0.13 crashes 100 million vehicle miles0.97281 0.95036 0 0.077121 14e= =( )
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112 Guide for the Analysis of Multimodal Corridor Access Management Carter et al. Pedestrian and Bicycle Intersection Safety Indices Carter et al.
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Applications Guidance for Selected Quantitative Analysis Methods 113 ( )
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114 Guide for the Analysis of Multimodal Corridor Access Management Carter et al.
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