Critical gap estimation at two-way stop-controlled intersections based on occupancy time data

摘要

Critical gap estimated at four Indian intersections using six popular techniques revealed a wide variation and many of these values are found to be unrealistically low. It indicates that all these methods are not adequate to address the complex traffic behaviour that exists in heterogeneous and non-lane-based traffic environment. A new method based on the occupancy time (OT) of a vehicle in the intersection area is proposed for the estimation of critical gap under mixed traffic conditions. The method is demonstrated to provide reasonably good results when applied to the data collected at one intersection in the US also. The correctness of the proposed method is further demonstrated by comparing the field capacity of a non-priority movement at one of the intersections with the theoretical capacity. It is found that the proposed method gives the capacity which is closer to field capacity than those estimated bythe maximum likelihood method or modified Raff method.