01630583

Component

This research presents a new methodology of PCU estimation using area occupancy as measure, particularly for heterogeneous and non-lane based traffic prevailing on multilane urban roads, especially under Asian specific conditions. The methodology presented here can also be applied to lane based traffic using time occupancy as measure of PCU estimation. In view of studying PCU values for non-lane based heterogeneous traffic scenario, two mid-block study sections on multi-lane urban roads in Indian city: Delhi (eight-lane divided carriageway) and Mumbai (ten-lane divided carriageway) were identified. A novel approach of matrix-solution to area-occupancy based simultaneous equations provides simplified but yet unique/optimized PCU values for different vehicle classes considering prevailing roadway and traffic conditions. It is found that increase in number of lanes or carriageway width has significant increasing effect on PCU values of vehicle categories. Further, the mixed-traffic flow expressed in PCU/hour/direction is validated with base-traffic flow under varying traffic-flow conditions. Mean Absolute Percentage Error (MAPE) after comparison was found to be 8 % and 9% for Delhi and Mumbai road sections, respectively, thereby indicating the robustness of the developed concept. For examining the accuracy of the proposed method at, speed-flow relationships are developed and compared on same set of axes using: (i) proposed unique (or optimized) PCU; (ii) dynamic PCU values (using most accepted speed-area ratio concept) and; (iii) PCU values from IRC-106, at 5-minute interval aggregation level. The comparison shows the difference of 2.0% and 1.3% at capacity level for Delhi and Mumbai sections, respectively for optimized and dynamic PCU concept. This further validates the reliability of proposed simplified yet vigorous methodology of PCU estimation as well as unique set of PCU values in comparison to other established method. PCU values in IRC-106 resulted in underestimation of capacity for ten-lane divided section but were consistent for eight lane divided section. This is due to the fact that same set of PCU values given in the IRC guideline, irrespective of carriageway width may not provide the accurate results.

This paper was sponsored by TRB committee AHB40 Standing Committee on Highway Capacity and Quality of Service.

01618707

17-03248

English

23p

2017

Transportation Research Board 96th Annual Meeting

Digital/other

Figures; References; Tables

Lane occupancy; Methodology; Passenger car equivalence; Traffic lanes; Urban areas; Vehicle classification; Vehicle mix

Delhi (India); Mumbai (India)

Highways; Planning and Forecasting

Transportation Research Board Annual Meeting 2017 Paper #17-03248

PRP, TRIS, TRB, ATRI

Dec 8 2016 11:13AM