Ontwikkeling van het rijden onder invloed tussen 1987 en 1989 : evaluatie van het effect van de vervanging van de bloedproef door ademanalyse per 1 oktober 1987.

This study describes the developments in driving while under the influence of alcohol (DWI) in the Netherlands after the introduction of the breath test as a legal proof per 1 October 1987. Two effect measurements of this introduction were conducted among a number of arbitrary car drivers during week-end nights in 1988 and 1989. The 1987 measurement was used as a before study. The publicity in the mass media on alcohol and traffic was studied in 1988 and 1989. The results of the alcohol measurements show a one-fourth reduction in DWI between 1987 and 1988, but no further decrease in 1989. The DWI decrease between 1987 and 1989 is caused particularly by a changed drinking behaviour of car drivers aged 50 years and older. The increased police enforcement seems to have played an important role in reducing DWI. This can be deduced from the fact that DWI increased in the provinces of both North Brabant and Limburg between 1987-1989. The results of the publicity study show that there were considerably less police enforcement activities in both provinces than in the rest of the Netherlands. Both national publicity campaigns and police enforcement are essential in order: (1) to maintain the 1988 and 1989 DWI level; and (2) to further decrease this relatively low level, if possible.