Development and assessment of a traffic adaptive control system in Korea

This paper addresses the outline of the traffic signal timing principles engaged in TRACS and the results of a field test. A research team, encompassing research institute, university and electronic company, conducted the three-year project for developing the new system, named TRACS (TRaffic Adaptive Control System). The project was successfully completed in 1994. TRACS aims at accomplishing the objectives of better traffic adaptability and more reliable travel time prediction. TRACS operates in real-time adjusting signal timings throughout the system in response to variations in traffic demand and system capacity. The purpose of TRACS is to control traffic on an area basis rather than an individual uncoordinated intersection basis. Another purpose of TRACS is to provide real-time road traffic information such as volume, speed, delay, travel time and so on. The performance of the first version of TRACS was compared to the conventional TOD control through a field test. The test result was promising in that TRACS consistently outperformed the conventional control method. The change of signal timing reacted timely to the variation of traffic demand. The feature of real-time travel-time estimation is under study