Adaptive control of isolated intersections based on sequential signal-stage optimisation

Abstract

Fluctuations in traffic flows at isolated intersections throughout the day have a negative impact on the control effects of certain traffic signal control methods. To solve this problem, adaptive signal control of isolated intersections based on sequential signal-stage optimisation is proposed under a multi-stage optimal decision framework to reduce vehicle delays and increase traffic efficiency. In this paper, to maximise the traffic capacity of an intersection during a signal stage, a primary and secondary control mechanism is designed in which the signal-stage phase (SSP) is composed of primary and secondary compatible phases. The SSP can be dynamically obtained and its maximum duration can be determined in a predictable manner. The terminal conditions are also designed to end the current SSP in a timely manner to increase the traffic throughput of an isolated intersection during a signal cycle. For easier understanding, the adaptive signal control algorithm is elaborated in detail. Numerous simulation experiments were performed in the Vissim 5.4 software program and the simulation results demonstrated that, compared with fixed timing control, segmented timing control and fully actuated control, the proposed control method can clearly reduce the average vehicle delay and the impact on average vehicle stops is acceptable.