A Framework for Analyzing Intersection Timing and Red Light Collisions

Abstract

It is not surprising that many multi-vehicle collisions occur at intersections, as intersecting streets present potential conflict situations where vehicle paths can cross one another. What does surprise both naïve observers and many professionals involved in accident investigations (e.g., accident reconstructionists, human factors scientists, lawyers) is the explanation that most red light running accidents happen only when the vehicle violating the red light enters the intersection approximately 4 to 6 seconds or more after the light has turned red. This paper provides a framework to study the conditions under which red light running collisions occur. This framework is applied to real-world intersection geometries and red light running collisions captured on video. A comparison of observational and crash data indicates that only a small fraction of red light running results in collisions. The mathematical framework can be used to develop likely timing scenarios in accident investigation, and can be expanded to study motor vehicle collisions with bicyclists or pedestrians.