From May 1, 1988 the speed limit on Dutch motorways was increased from 100 to 120 km/h. For a limited part of the motorway network the limit is still fixed at 100 km/h. The introduction of this modification in the speed limit was attended by information, publicity and an increased police enforcement. In the middle of 1989, a first global evaluation of the effects of these measures on the traffic safety was carried out. This investigation is a continuation of the evaluation study using 1989 data, and a limited number of 1990 data. It is concluded that: (1) the composition of measures has produced a decrease in the actual driving speeds, despite the speed limit increase; (2) the decrease in speed has caused a notable increase in traffic safety; (3) this effect on traffic safety is rather temporary; (4) the safety effects are not only limited to motorways, but also to other road types; and (5) the speed limit increase has not produced negative consequences in the longer term.
Abstract