Traffic-Actuated Signal Control Based on Dynamic Optimal Maximum Green Time

The parameter of greatest importance to actuated signal control is the maximum green time. This paper presents two approaches to optimize maximum green time estimation. One is single-objective adaptive model based on HCM delay formula minimizing intersection average delay; the other is multi-objective analytical model minimizing delay-and-stops in unsaturated conditions and maximizing capacity in saturated conditions. The current cycle length is calculated by the proposed model and then is assigned to design optimal maximum green time based on equal degree of saturation principle. The maximum green time is adjusted cycle-by-cycle, varying with traffic conditions. Simulation results show that the proposed methods are capable of adjusting signal timing in response to the change of traffic conditions, and are effective to improve the performance of actuated control.