Measuring the Performance of Bus Rapid-Transit Corridors Based on Volume by Capacity Ratio

Abstract

Various approaches have been deployed for evaluating the performance of bus rapid transit (BRT) systems based on qualitative, economic and quantitative parameters. In the present study, the performance evaluation of the bus rapid transit system (BRTS) in Indian cities using a microsimulation technique has been attempted. Base networks of Delhi and Ahmedabad BRT corridors were developed, calibrated, and validated using specialized software. After the validation process, speed versus volume to capacity (V-C) ratio equations were developed for mixed vehicle (MV) and bus lanes, respectively, of both the corridors considered in the study. These equations were optimized to find out the optimum value of V-C ratio on the MV and bus lanes, which were found to range between 0.64 and 0.75. An average value of 0.688 V-C ratio was derived in this study for BRTS based on the calculated optimal values. Then, the concept of user equilibrium (UE) was deployed to understand when the travel speeds in both an MV lane and a bus lane of a BRT corridor reach the point of congestion. Based on this study, it can be concluded that 0.688 V-C ratio is the optimal flow value for BRT corridors. This implies that up to 0.688, both the MV lane users and bus lane users will enjoy reasonable travel speeds and smaller delays. If the V-C ratio is exceeded on either bus lane or MV lane(s), then the BRT system becomes untenable for the MV lane and bus lane users, instead creating traffic congestion.