Traffic signal timing at isolated intersections using simulation optimization

Abstract

Two innovative stochastic traffic signal optimization techniques for isolated intersections are discussed. The objective is to determine the optimum cycle and green phase lengths for signalized isolated traffic intersections. Determination of optimum cycle and green phase lengths is based on minimization of the total average delay at the intersection for a given period of observation. Traffic signal timing is formulated as a stochastic inventory problem, which is then solved by a combination of simulation and dynamic programming. The suitability of the optimization techniques for undersaturated and oversaturated flow conditions; and steady state and nonstationary queue conditions are discussed. The advantages of the techniques over most widely used signal optimization methods, and the application of the simulation optimization method in state dependent server-vacation signal timing are also discussed.