URBAN MOTOR-VEHICLE CRASHES AND POTENTIAL COUNTERMEASURES

Despite advances in highway safety, motor vehicle crashes remain the l eading cause of injury death in the United States. Urban areas have th e highest rates of injury crashes. The problem of urban crashes can be addressed through implementation of changes to the roadway environmen t. Collision classification systems based on reliable and detailed inf ormation can be used to develop countermeasures for urban crashes. Thi s paper provides a brief review of recent efforts to classify motor ve hicle crashes and identifies countermeasures that might reduce the fre quency and severity of urban crashes. The most common circumstances of urban crash events include drivers disregarding traffic controls, rea r-end collisions, and crashes in which a left-turning vehicle disregar ds the right-of-way of opposing traffic. Countermeasure efforts should focus on urban intersections and management of vehicle speeds. Specif ic countermeasures include lengthening clearance intervals, improving visibility of traffic signals, use of red-light cameras, wider applica tion of multiway stop control, improved timing of traffic signals to r educe vehicle stops, installation of left-turn lanes, and conversion o f intersections to traffic circles.