Research on the relationships between the speeds at which drivers are prepared to drive and the accidents in which they are involved has been undertaken at the aggregate level and the individual driver level. Both types of study have shown significant relationships between accidents and the speed measures used. An understanding of the links between the individual and aggregate speed-accident relationships could be fairly important for developing accident countermeasures. This paper describes the aggregate studies, briefly reviews the individual studies, and proposes a framework for modelling speed-accident relations in the light of findings from both types of study. It seems reasonable to suppose that the relations depend on the road or junction type, or more generally the road geometry, traffic levels, the speed choice characteristics of drivers using the road, and the severity of the accidents being considered.
Abstract