In February 1998, an ambitious project with intensified police surveillance began in the northern province of Friesland. It was called "Frisian Dykes". This report describes an evaluation study into the effects of intensified police surveillance on speeding, drunken driving, seat belt use, and the number of accidents. The intensified surveillance of speeding resulted in a significant reduction in the percentage of offenders on most of the road stretches during the first fifteen weeks. After this, the driving speeds more or less stabilised. Driving under influence does not appear to be declining in Friesland, as it is doing in the rest of the Netherlands. It also appears that the concentration of drunken driving is still moving from middle-aged to young, male drivers. Because of this, the accident ratios of drunken driving are still increasing. For determining seat belt use, only one pre-measurement was made. The safety increased slightly along the road stretches with intensified surveillance. This improvement, however, is not statistically significant. This is a positive result when compared with the negative safety developments on the rural, provincial roads without intensified surveillance. This result is also positive when compared with a general decline in road safety in the whole of the province.
Abstract