California Partners for Advanced Transportation Technology

This paper introduces an adaptive signal control system utilizing an on-line signal performance measure. Unlike conventional signal control systems, the proposed method employs 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 utilizing direct intersection delay measures. A description of the overall control system architecture and the optimization algorithm is addressed in this paper. Performance of the proposed system is evaluated with a high-performance microscopic traffic simulation program, Paramics, and the preliminary results have proven the promising properties of the proposed system. Key Words: adaptive signal control; vehicle re-identification; intersection delay estimation; signal plan optimization