Post impact travel and secondary impacts following urban intersection collisions

Abstract

This paper describes the path of vehicles following a collision with another vehicle at a metropolitan intersection. The aim was to provide guidance to transport authorities on roadside design at intersections to protect vehicles from secondary collisions with roadside objects. Detailed information from in-depth investigations of 78 intersection crashes were analysed. Crashes at signalised and unsignalised intersections were analysed separately. Secondary collisions with roadside objects were identified with 16 signalised and 16 unsignalised intersection cases. Nine of these 32 collisions were more severe than the initial vehicle-to-vehicle collision, three at signalised intersections and six at unsignalised intersections. Of the 78 intersection crashes, more than half of the vehicles came to rest within 10 metres of the impact point. More than a quarter travelled 15 metres or further and approximately 10% travelled further than 27 metres. It was found that 28 of the 70 crash involved vehicles at signalised intersections encroached into the designated pedestrian crossing areas. It was also found that 10 of those vehicles departed the roadway. The study has indicated the most likely locations that vehicles will traverse following collisions at urban intersections. This information can be used by road designers to make decisions in relation to the protection or removal of roadside objects in the vicinity of intersections.