Iterative Tuning Strategy for Setting Phase Splits in Traffic Signal Control

This paper introduces Iterative Tuning (IT) strategy for urban traffic signal control. This strategy is motivated by people's daily repetitive travel patterns between homes and working places. Statistical analysis of a real traffic network shows that traffic flows of junctions are repetitive with small variations on a weekly basis. The main idea of IT is that, daily traffic signal schedules are tuned with anticipation of traffic demands. In this paper, only phase split is tuned iteratively to balance the traffic demands from all directions in a junction. Each junction has its own controller and these controllers can work cooperatively to improve the network performance after several iterations. Therefore IT strategy is scalable for arbitrary large urban networks. Marina Bay and Clementi areas in Singapore based on real traffic data are simulated and simulation results show that IT strategy can improve the performance considerably comparing with fixed-time strategy.