Center for Traffic Simulation Studies

This paper introduces an adaptive signal control system that utilizes an on-line signal performance measure. Unlike conventional signal control systems, the proposed method uses real-time delay estimation and an on-line signal timing update algorithm. As a signal performance measure, intersection delay for each phase is measured in real-time via an advanced surveillance system that re-identifies individual vehicles both at upstream and downstream stations using vehicle waveforms obtained from advanced inductive loop detectors. In each cycle, the signal timing plan is optimized based on the delay estimated from the vehicle re-identification technology. The main thrust of the algorithm is the on-line control capability that utilizes direct intersection delay measures. A description of the overall control system architecture and the optimization algorithm is presented. The performance of the proposed system is evaluated with a high-performance microscopic traffic simulation program, Paramics. Preliminary results have proven the promising properties of the proposed system.