Detection, Control, and Warning System for Mitigating Dilemma Zone Problem

High-speed signalized intersections present a grave hazard to the traveling public. An important component of this hazard is variation in the process of deciding whether to stop or proceed that occurs in the dilemma zone. To mitigate the dilemma zone problem, an innovative vehicle-specific detection, control, and warning system (DCWS) is being developed. To reduce dilemma zone conflicts, DCWS uses detection of individual vehicle speeds to provide unique, speed-specific dilemma zone protection for each vehicle as it approaches a signalized intersection. Although protecting all vehicles would be ideal, under some situations such protection is not possible. To account for these situations, DCWS also uses a vehicle-specific in-pavement system to give advance warning to drivers who are going to be trapped in the dilemma zone. With hardware-in-the-loop simulations, the new DCWS outperforms conventional dilemma zone warning systems in terms of the number of vehicles in the dilemma zone, the number and percentage of vehicles requiring warning, and the number of warning events per hour.