A stable longest queue first signal scheduling algorithm for an isolated intersection

Abstract

There have been countless efforts directed toward efficiently controlling the flow of traffic through an intersection. This paper describes an algorithm designed for the signal control problem that employs concepts drawn from the field of computer networking. The novel method proposed utilizes a maximal weight matching algorithm to minimize the queue sizes at each approach, yielding significantly lower average vehicle delay through the intersection. Lyapunov function-based analysis is provided, deriving the conditions under which the system is guaranteed to be stable. The algorithm is compared to an optimized fixed time controller using the VISSIM traffic simulation environment. Simulation results clearly demonstrate the performance gain obtained when using the proposed scheme, particularly in the presence of the non-uniform traffic scenario proposed.