Skip to main content

Report finds speed cameras reduce crashes, injuries in DC

A new report carried out by Parsons Brinckerhoff on behalf of the DC Department of Transportation (DDOT) finds that speed cameras are helping to reduce accidents and injuries and slowing drivers down. The DDOT conducted an engineering study to determine a link between traffic safety and placement of automated speed enforcement devices (speed cameras) in the District of Columbia. As part of this study, Parsons Brinckerhoff and its team members conducted speed and volume studies, carried out field assessme
February 10, 2014 Read time: 3 mins
A new report carried out by 4983 Parsons Brinckerhoff on behalf of the DC Department of Transportation (DDOT) finds that speed cameras are helping to reduce accidents and injuries and slowing drivers down.

The DDOT conducted an engineering study to determine a link between traffic safety and placement of automated speed enforcement devices (speed cameras) in the District of Columbia. As part of this study, Parsons Brinckerhoff and its team members conducted speed and volume studies, carried out field assessments, reviewed speed data and analysed crash data at 295 speed camera locations in the District of Columbia with the aim of using real-world data to establish the speed nexus at each of the enforcement locations.

Historical crash data shows that there were a combined total of 2,240 crashes occurring at these locations prior to speed camera installation. The number reduced to 1,863 crashes after speed camera installation. A combined total number of injury crashes prior to speed camera installation was 841 compared with 673 after installation of the speed camera.  The number of injuries also decreased by 20 per cent, from 1,251 prior to installation to 996 after installation. Further crash data analysis revealed that the number of crash types also reduced over the period of time since speed cameras were installed at these locations.

Based on the analysis results from the speed data analysis, the crash data analysis, the field assessments results, and engineering judgment, the team was able to determine the nexus between traffic safety and the speed camera at all 295 existing, planned, and proposed locations. It was found that at most of the locations, the speed data alone or the crash data alone provided sufficient results to determine a safety connection. There were a number of locations where both the speed data and crash data results provided more than enough information to support a safety correlation. This was apparent at most of the freeway locations, and the high accident locations around the District. At many of the sites that were located in residential areas, the field assessments and engineering judgment was heavily relied upon to determine safety link. Overall, a technical justification is provided for all speed camera locations.

The report concludes that the results of the study can be used to establish a connection between traffic safety and the placement of automated speed enforcement devices in the District of Columbia.

Related Content

  • October 31, 2016
    Average speed cameras reduce injury collisions, says report
    Research carried out into average speed camera (ASC) effectiveness by the UK’s RAC Foundation concludes that the implementation of ASCs in the locations that have been assessed in its report has had the effect of reducing injury collisions, and especially those of a higher severity. Even taking into account other influencing factors, the report says the reductions are large and statistically significant. Researchers analysed detailed accident data taken from 25 sites where average speed cameras were inst
  • June 10, 2014
    Independent analysis finds speed cameras do not reduce accidents
    An independent analysis carried out by engineer Dave Finney of Thames Valley, UK speed camera data has found an increase in injuries after the devices were installed. The analysis, to evaluate the effect of fixed speed cameras on the number and severity of collisions at the sites where they are installed, was carried out on two groups of sites. One group includes all fixed speed camera sites in the Thames Valley area (covering Oxfordshire, Buckinghamshire and Berkshire) that were active at the start of 2
  • November 28, 2012
    Canadian authorities convinced of enforcement safety benefits
    Cost-benefit analysis invariably finds highly in favour of speed and red light enforcement, particularly so in Edmonton in the Alberta province of Canada, where authorities need no convincing of the merits of road safety engineering. Justification of enforcement efforts on economic grounds has been reinforced this year, by a study of the costs and benefits of red light enforcement. New York-based economic research firm John Dunham & Associates carried out this latest analysis for American Traffic Solutions
  • July 28, 2015
    Latest A9 speed camera report ‘shows improvement in driver behaviour’
    The latest performance data for A9 speed camera system has been published by Transport Scotland on behalf of the A9 Safety Group, covering the period May 2015 to July 2015 (incidents are quarter two April to June) as an overall assessment of the performance of the route. The report incorporates the first information in relation to collision and casualty figures covering the period from October 2014 to March 2015, which are reported against the average of the equivalent months in the preceding three year