Effects of average speed enforcement on speed compliance and crashes: A review of the literature

  • Published: Accident, analysis and prevention, 54, 46-56 (2013)
  • Authors: Soole, D.W., Watson, B.C. & Fleiter, J.J.
  • Date Added: 05 Apr 2016
  • Last Update: 05 Apr 2016
  • Format: html


Review of the evidence regarding the impact of average speed cameras in reducing vehicle speeds and its impact on crash rates and road safety.

Methodology:     Identified relevant studies through a systematic search of key road safety databases (Science Direct, TRID, ATI). The reference lists of all retrieved research were also used and cross referenced for relevant studies. In addition grey literature was included (retrieved from key road safety organisations, police and transport authorities, manufacturers).

Key Findings

  • Average speed enforcement was found to have a positive influence on speed reduction and road safety in general. It was found to reduce mean speed and 85th percentile vehicle speeds by up to a third.

  • They show an increased compliance with the speed limit as well as decrease in speed variability.

  • Similarly they have been found to reduce the levels of KSI (between 33% and 85% reduction).

  • In addition, they have been found to be more well received by drivers who consider them as fairer as they monitor behaviour over a longer period of time and not at a single moment in time which may poorly reflect overall driving behaviour.

  • In addition, the use of average speed cameras has reduced the stop-start motion often found with fixed and mobile speed cameras reducing speed variability and in turn improving traffic flow.  


Average speed enforcement, speed enforcement, speed cameras, literature review