Setting All-Red Clearance Interval Based on Traffic Conflict Technique at Signalized Intersection

Crashes caused by red light violations (RLV) are often associated with injuries and in some instances fatalities. Low cost safety treatments at signalized intersections are effective in mitigating traffic crashes and injuries. It is well known that the duration of all-red clearance interval is one of the more significant factors involving low cost safety treatments. Appropriate all-red clearance interval would improve the safety of a signalized intersection. However, in the absence of a well designed, all-red interval, these vehicles run the risk of a collision with the cross-street vehicles since they will be traveling during the green light. The research presents a method to determine all-red clearance interval based on avoiding traffic conflicts between an exiting traffic stream and an entering traffic stream. Compared to the other method of calculating all-red clearance interval, the conflict zone approach is more applicable, better reflecting intersection geometry and controls sequence. It considers the traffic operations at an intersection in more detail and takes into account both the exit and the entrance time.