Despite advances in highway safety, motor vehicle crashes remain the leading cause of injury death in the United States. Urban areas have the highest rates of injury crashes. The problem of urban crashes can be addressed through implementation of changes to the roadway environment. Collision classification systems based on reliable and detailed information can be used to develop countermeasures for urban crashes. This paper provides a brief review of recent efforts to classify motor vehicle crashes and identifies countermeasures that might reduce the frequency and severity of urban crashes. The most common circumstances of urban crash events include drivers disregarding traffic controls, rear-end collisions, and crashes in which a left-turning vehicle disregards the right-of-way of opposing traffic. Countermeasure efforts should focus on urban intersections and management of vehicle speeds. Specific countermeasures include lengthening clearance intervals, improving visibility of traffic signals, use of red-light cameras, wider application of multiway stop control, improved timing of traffic signals to reduce vehicle stops, installation of left-turn lanes, and conversion of intersections to traffic circles. (A)
Abstract