Rijden onder invloed in de provincie Noord-Holland, 1997-1998 : ontwikkeling van het alcoholgebruik door automobilisten in weekendnachten. In opdracht van Directoraat-Generaal Rijkswaterstaat, Directie Noord-Holland.

In October 1998, 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 North Holland. Blood alcohol content (BAC), age and sex of the drivers were collected and recorded. If the recorded BAC level was 0.7 promille or over, places of origin of the offenders were also collected and recorded. The study was carried out on Friday and Saturday nights. The 1998 sample included 2558 motorists. The collected data were analysed using the Weighted Poisson Model (WPM). The results of the 1998 survey are compared with the results of the 1997 survey and with the results of the 1997 national survey.