Assessment of the Suitability of Microsimulation as a Tool for the Evaluation of Macroscopically Optimized Traffic Signal Timings

Abstract

In practice, traffic signal timings are derived using macroscopic tools that are essentially deterministic. Traffic flows, signal phasing, and street geometry are processed to deliver optimized signal timings. Objective functions strive for efficiency through minimizing measures such as delay and journey time. We now have traffic microsimulation tools that model traffic by imitating its stochastic nature. This paper looks at microsimulation as a means of testing optimized signal timings. We assess the suitability of evaluating signal timings optimized macroscopically through microsimulation. We analyze a range of traffic demand and traffic control scenarios. A real-world arterial with 12 signalized intersections serves as a test bed for the experiments. The results show that when macroscopically optimized signal timings are subject to extensive evaluation through microsimulation, their efficiency is shown to be inconsistent. The paper concludes that the traffic microsimulation tools cannot always be relied upon to evaluate macroscopically optimized traffic signal timings because these timings sometimes perform worse, in microsimulation, than the nonoptimized signal timings.