Enhanced crash investigation study report 2 - Speed crash risk and injury severity

This report examines the role of speed in shaping crash risk and injury severity. The report examines five key questions: 1. The relationship between the speed limit and travel speed; 2. The relationship between travel speed and the risk of involvement in a crash that results in one or more involved drivers being hospitalised; 3. The relationship between travel speed and vehicle speed at impact, the frequency of  pre-crash avoidance actions and the effect, if any, of these actions on the speed of the vehicle at impact; 4. The relationship between impact speed and injury severity, and 5) The injury reduction benefit of lower impact speeds. A case series approach was used to illustrate the potential benefits of reduced travel speed, speed limit compliance and impact speed on crash and injury severity outcomes.

Key inputs to this analysis are the estimates of travel speed and impact speed obtained through the crash reconstruction process and the ‘free travel speed’ data obtained from ECIS Control Study drivers.

The Report presents practical examples of the effect of reducing travel speed on crash outcomes using crash reconstruction methods.