Automatic Speed Management in the Netherlands

Abstract

Speed warnings and enforcement can be administered locally on a road stretch, and on a road network. Local automatic speed warning at an urban intersection reduced the mean speed by 5 km/hr. Theoretically, a reduction in accidents of 25 to 65 percent can be achieved. At a rural intersection, the speed limit was reduced from 100 to 70 km/hr. An automatic sign warns speeding cars; this resulted in a lowering of the mean speed from around 80 to 63 km/hr. An automatic speed warning and enforcement system on two-lane rural road stretches where the speed limit is 80 km/hr resulted in a reduction of the mean speed from 78 to 73 km/hr; the percentage of speeders decreased from 40 to 10 percent. The total number of accidents was reduced by 35 percent. This effect was almost the same three years after concluding the experiment. The problem of vandalism could be diminished by mounting the camera on a high pole, mechanically preventing climbing of the pole, automatic detection of vandalism, and wireless communication to a nearby police station. Enforcement of speed on a provincial road network using radar and camera exclusively from a parked unmarked car was conducted in three provinces. A sign downstream of the enforcement site read “Your speed has been checked. Police.” Periodic information campaigns were conducted to increase awareness of the risk of being caught. The result was a reduction of average speed by 4 to 5 km/hr, although the percentage of speeders is still high a reduction from 40 to 30 percent. This type of enforcement is accepted by 75 percent of the drivers. Greater priority for speed enforcement is needed in addition to automating enforcement and processing to increase efficiency.