A photo-radar enforcement van reduced the number of speeding vehicles in a work zone by 24 percent.
Experience with automated enformcent in Oregon.
Made Public Date
The control area included a two mile work zone subject to heavy traffic and frequented by large trucks. Traffic sensors were inconspicuously mounted on available utility poles in the study area to measure traffic volumes, vehicle speeds, lane occupancy, and vehicle classifications before, during, and after photo-radar speed enforcement vans were deployed and enforcement warning signs posted in the work area

Key data collection periods:
  • Prior to work zone and photo-radar enforcement (November 2008 to March 2009)
  • After the work zone was established, but before photo-radar enforcement was implemented (March 2009 to September 2009)
  • After the work zone was established and during periods with photo-radar enforcement (March 2009 to mid-September 2009)
  • After photo-radar enforcement equipment and signs were removed (late-September 2009).
With a posted speed limit of 40 mi/hr and an average speed of 45 mi/hr measured in the work zone prior to enforcement, the percentage of vehicles traveling faster than 45 mi/hr was used to measure impacts.


During photo-radar speed enforcement speeding was reduced by an average 23.7 percent at the detection site within the work zone. The observed speeding reduction, however, was temporary and did not persist beyond the departure of the photo radar enforcement van.
Goal Areas
Deployment Locations