This paper describes the evaluation of one of the first region-wide enforcement projects, a pilot-project in the province of Friesland which started in 1998 and which preceded the large scale national programme which was to follow. The evaluation study covered a five year period of intensified speed enforcement along 28 above-average dangerous road stretches of the rural network with mainly unobtrusive mobile radar equipment. In co-operation with the Dutch Bureau of Traffic Enforcement, SWOV Institute for Road Safety Research carried out the present evaluation. In the first three years of the project an annual average of about 4500 effective control hours was sufficient to bring down substantially the level of speed offenders on the checked road segments. Statistical analysis could not detect a significant differences between decrease in speeding on enforced and non-enforced 80 km/h roads. Despite this lack of hard evidence, there are indications that suggest that enforcement indeed has made a difference. First, the decreasing trend in speeding in absolute numbers was larger on 80 km/h than on non-enforced 80 km/h roads. The fact that there was also a decreasing trend on non-enforced roads may have to do with a spill-over of enforcement. Since both on enforced and non-enforced roads the decreasing trend started in 1998, the first year of the enforcement programme, such an spill-over effects seems likely. Second, the general decreasing trend in speeding which started in 1998 cannot likely be explained by any other factor than enforcement. In the year 1998 there was not a large scale provincial road safety programme focused on roads outside urban areas, and there was not a drastic changes in mobility in. What we know from the psychology of drivers is that they do not ""spontaneously"" turn into safe drivers without any change in the road environment. If police enforcement did not play a substantial role in reducing speeds on the roads in Friesland, we are at a loss to suggest an alternative explanation. Based on the available data, the best possible estimate of the 5-year traffic safety effect of the enforcement programme has been a 21% reduction of serious casualties and a 21% reduction of injury accidents as a result of crashes with motorised traffic.nts translates into the extra saving of about 35 serious casualties and 50 injury accidents. Due to the limited number of fatalities we did not perform any separate analysis on reduction of fatalities. However, with an estimated reduction of 35 serious casualties, it seems highly likely that between 3-5 fatalities have been saved. For the covering abstract see ITRD E136183.
Abstract