Delay at Signalized Intersections under Mixed Traffic Conditions

Abstract

Delay caused to an individual vehicle at a signalized intersection is a performance measure to assess the level of service. While dealing with delay in Indian traffic conditions, researchers generally opt for either the U.S. Highway Capacity Manual (HCM) or Webster’s delay model. However, these models, developed on the basis of homogeneous traffic conditions, yield erroneous results for developing countries where the traffic is highly heterogeneous with almost no lane discipline. In this context, the present study presents an improved delay model for signalized intersections under heterogeneous traffic conditions. The proposed model has been developed by modifying the existing HCM model on the basis of traffic data collected from seven four-legged signalized intersections across the country. Measured queue length was plotted with time and Simpson’s one-third rule was used to estimate the total delay in a cycle and average delay per vehicle. The proposed model is validated by using the data of eight other intersections and the maximum difference between the observed delay and estimated delay is found to be less than 5%.