Rijden onder invloed in de provincie Gelderland, 1993-1994 : de ontwikkeling van het alcoholgebruik van automobilisten in weekendnachten. In opdracht van Directoraat-Generaal Rijkswaterstaat, Adviesdienst Verkeer en Vervoer AVV en Directoraat-Generaal Rijkswaterstaat, Directie Gelderland.

In the months September and October 1994, the SWOV Institute for Road Safety Research and eight police control teams conducted a roadside survey. The aim was to establish the motorists' alcohol consumption in the Dutch province of Gelderland. Blood alcohol content (BAC), age and sex of the drivers were collected and recorded. If the recorded BAC level was 0.7 or over, places of origin of the offenders were also collected and recorded. The study was carried out on Friday and Saturday nights. The 1994 sample included 1944 motorists. The results of the 1994 survey are compared with the results of the 1993 survey