Experience with automated speed enforcement in Norway.
Norway
Effects on Accidents of Automatic Speed Enforcement in Norway
Summary Information
This study examined the use of automated speed enforcement in Norway. The system was designed to photograph drivers and license plates of vehicles who triggered speed detection settings calibrated above the posted speed limit by police. If vehicle license plate numbers were visible, a standard traffic ticket was issued to the owner. If the owner denied the charges, the law required the owner to identify the driver. The objective of this study was to observe changes in accident rates, vehicle speeds, and property damages before and after photo radar gun deployment on 64 warranted and non-warranted roadway sections.
- The mean traffic speed on the road section was greater than the posted speed.
- The road section had an accident density of at least 0.5 injury accidents per km of roadway.
- The accident rate on the road section was higher than the normal accident rate for that type of road.
The road sections in this study ranged from 0.56 kilometers (km) to 20.0 km in length. The average "before" period was 3.94 years, and the average "after" period was 4.61 years. The data collection effort was completed by 1996.
As a result of limited “before” data related to vehicle speeds and property damage, the evaluation focused primarily on changes in accident rates.
RESULTS
After the deployment of automated speed enforcement the number of injury accidents declined by 20 percent. However, this reduction varied depending on whether the roadway segment met Norway’s warrants for deployment of automated speed enforcement.
- On roadway sections meeting the warrants injury accidents declined by 26 percent.
- On roadway sections not meeting the warrants injury accidents declined by 5 percent.