Speed cameras in Montgomery County, Maryland reduce crashes resulting in fatal or serious injuries by 49 percent.

Study in Maryland evaluates the long-term effects of a speed camera program on travel speeds, public attitudes, and crashes.

August 2015
Montgomery County,Maryland,United States

Summary Information

Montgomery County, MD began implementing automated speed enforcement cameras back in 2007. An evaluation of the county’s camera system was conducted by the Insurance Institute for Highway Safety in 2014.

  • 56 fixed cameras, 30 portable cameras and 6 mobile speed vans were installed in school zones and residential streets with speed limits of 35 mph or less (camera use was limited by state statute).
  • Travel speeds at camera sites were measured in September 2006 (6 months before the speed camera program began) and November 2014 (7.5 years after the speed camera program began). Changes in measured travel speeds were then compared with changes in speeds at control sites in the nearby Virginia counties of Fairfax and Arlington.
  • Using crash data from the years 2004-2013, logistic regression was conducted to examine the effects of the program on the likelihood that a crash involved an incapacitating or fatal injury and on the likelihood that a crash was speeding related on camera-eligible roads. Crash data from Fairfax County was used as controls.
  • A telephone survey of Montgomery County drivers was conducted in fall 2014 to examine attitudes and experiences related to automated speed enforcement.
  • Overall mean speeds decreased by 10 percent.
  • Those speeding 10 mph or more decreased by 59 percent.
  • Crashes resulting in fatal or serious injuries on speed camera roads decreased by 49 percent.
  • The speed cameras were associated with a 19 percent reduction in the likelihood that a crash resulted in an incapacitating or fatal injury.
  • Of the drivers surveyed, 62 percent were in favor of the county’s speed camera system.

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Effects of Automated Speed Enforcement in Montgomery County, Maryland, on Vehicle Speeds, Public Opinion, and Crashes

Author: Wen Hu, Anne McCartt

Published By: Insurance Institute for Highway Safety

Source Date: August 2015



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Benefit ID: 2015-01018