Speed enforcement cameras can reduce injury crashes by 20 percent.

Experience using speed cameras to promote safety in the District of Columbia.

Washington DC,District of Columbia,United States

Summary Information

This study evaluated the connection between automated enforcement and safety at existing and planned automated speed enforcement locations in the District of Columbia. Field assessments were to account for roadway geometry, land use, and other exogenous factors, and independent researchers were consulted to analyze impacts on then traffic speeds, volume, and crash data before and after speed cameras were installed.

A variety of data were collected to evaluate trends, performance, and safety impacts. Approximately 295 sites were evaluated including 169 sites with cameras proposed, 37 sites with cameras planned, and 87 sites with cameras installed.

Accident Reports
Traffic Data
Speed Data
Location of Speed Cameras
Crash data for all speed camera locations

Before and after crash data for existing speed camera locations

2009-2011 Traffic Safety Statistics Report

2011 Highway Safety Improvement Program Report (HSIP)

2012 Highway Safety Improvement Program Report (HSIP)

2014 Highway Safety Performance Plan

DDOT Strategic Highway Safety Plan (SHSP)

2010, 2011, 2012 Top 5 Percent High Accident Locations Map
2010 Traffic Volume Map

2011 Traffic Volume Map

2012 Traffic Volume Map
2010 DC Speed Study

2006 DC Speed Study

2006 DC Speed Study Map

Speed Camera Data
Installation Date for Existing Speed Camera Locations

Signal Timing Data

List of Signalized Intersections

Signal Optimization Report

Researchers analyzed historical data and collected traffic data to assess performance and quantify safety benefits after cameras were installed. Automatic traffic data recorders (ATRs) were used to collect data on vehicle speeds and traffic volumes, and the data collected were compared to the posted speed limits to determine if speeding decreased or continued to be problem at each site.

The safety assessment included an analysis safety records collected before and after the deployment. Researchers reviewed crash types, crash frequency, and crash severity data, and considered additional factors such as the day and time of crash, weather conditions, surface conditions, and lighting to identify any trends.

  • The total number of crashes at locations selected for automated enforcement decreased from 2,240 prior to installation of speed cameras to 1,863 after the installation (17 percent decrease).
  • The total number of injury crashes at these locations decreased from 841 prior to installation to 673 after installation (20 percent decrease).
  • The total number of injuries at these locations decreased from 1,251 prior to installation to 996 after installation (20 percent decrease).

Benefit Comments

No comments posted to date

Comment on this Benefit

To comment on this summary, fill in the information below and click on submit. An asterisk (*) indicates a required field. Your name and email address, if provided, will not be posted, but are to contact you, if needed to clarify your comments.


Speed Limit and Safety Nexus Studies for Automated Speed Enforcement for the District of Columbia

Author: Cheeks, James,

Published By: District Department of Transportation

Prepared by Parsons Brinckerhoff

Source Date: 01/05/2014



Average User Rating

0 ( ratings)

Rate this Benefit

(click stars to rate)

Goal Areas


Typical Deployment Locations

Metropolitan Areas


photo enforcement, speed cameras, automated speed enforcement, automated enforcement, photo radar

Benefit ID: 2014-00898