White Rose University Consortium logo
University of Leeds logo University of Sheffield logo York University logo

Effects of speed limit enforcement cameras on accident rates

Hess, S and Polak, JW (2007) Effects of speed limit enforcement cameras on accident rates. Transportation Research Record, 1830. 25 - 34 . ISSN 0361-1981


Download (187Kb)


Speed limit enforcement cameras (SLECs) have been in operation in Great Britain since 1991. However, there is still considerable dispute regarding their effectiveness in reducing accident rates. The aim of this research was to analyze the effects of SLECs on accident rates in Cambridgeshire,United Kingdom, using time series data collected over an 11- year period. A time series analysis of the accident data revealed the presence of both trend and seasonality components. A method was developed to remove the influence of these two components from the data and compare mean accident levels before and after installation of the camera. The method was also constructed in such a way that it would be able to distinguish between the actual effects of the camera installation and the effects of regression to the mean. The initial investigation into the effects of SLECs showed an average decrease over sites in the monthly accident frequency by around 18%; a more detailed analysis suggested that the best approximation of the effect of the introduction of a SLEC is a decrease in injury accidents by 31.26%, thus giving clear evidence that SLECs do indeed contribute to a significant decrease in accident numbers.

Item Type: Article
Copyright, Publisher and Additional Information: © 2007 National Academy of Sciences. This is an author produced version of a paper accepted for publication in Transportation Research Record. Uploaded in accordance with the publisher's self-archiving policy.
Institution: The University of Leeds
Academic Units: The University of Leeds > Faculty of Environment (Leeds) > Institute for Transport Studies (Leeds)
Depositing User: Symplectic Publications
Date Deposited: 19 Mar 2012 11:00
Last Modified: 01 Oct 2014 07:38
Published Version: http://dx.doi.org/10.3141/1830-04
Status: Published
Publisher: National Academy of Sciences
Refereed: Yes
Identification Number: 10.3141/1830-04
URI: http://eprints.whiterose.ac.uk/id/eprint/43617

Actions (repository staff only: login required)