Optimization of Coordinated Traffic Signal Timings in Urban Road Network

Abstract

This paper describes a new method of optimally coordinating the traffic signal timings. The optimization is based on the information available from the vehicle detectors in urban road networks in Japan. The conventional methods are deficient in that the cycle length and the split are characterized only by the behavior of critical intersection, and offsets along a major road are chosen from a small set of prescribed patterns. In the first step of the proposed method, the cycle length and the split are obtained by minimizing the total traffic delay in a sub-area which consists of a series of intersections. In the second step, the offsets are determined by maximizing the bandwidth that is the fraction of a cycle in which vehicles may pass through all intersections in the sub-area without stopping. The results of simulation experiments indicate that the proposed method reduces the queue length significantly in comparison with the conventional methods.