Driving Under the Influence of Alcohol
R in 't Veld, Ministry of Transport, AVV, NL
Since the nineteen-seventies, surveys were carried out to assess the alcohol consumption of car drivers. These studies had always been carried out by the Dutch Road Safety Institute (SWOV). From 1999, the governmental Transport Research Centre (AVV) has carried out these studies.
By the early nineties, not only national trends in drink driving but also developments on the provincial level could be tracked, due to the rise in the number of random sobriety checks performed. Toward the latter part of that same decade, the random sample encompassed some 20,000 to 30,000 roadside checks, which made it possible to draw conclusions at the level of the majority of the 25 police districts as well.
In the Netherlands, the figures for driving while intoxicated fell in weekend nights from 4.6 % in 2000 to 4.2% in 2001. Due to the number of checks, this may be regarded as a significant reduction.
A positive effect of stepping up enforcement is clearly noticeable. In 2001, the percentage of drivers under the influence of alcohol in districts where the special enforcement teams were put in place, was found to have declined that first year by 15%. The study in the previous year had led to a comparable conclusion. When the Enforcement teams will be national implemented, it may be expected that the percentage of drink drivers shrink the following year in the other regions as well. However, it was shown that this decline will subsequently taper off in the second year after stepping up enforcement.
The figures over the last few years show, that the majority of drivers under the influence participating in traffic at night during weekends were found to have been visiting a licensed establishment of some kind. An additional 5% had just come from the canteen at their sports club.
Relatively high percentages of offenders were found: ? between 2.00 and 4.00 a.m. (Friday nights between 10 and 11% and Saturday nights round 8%); ? among male drivers between the ages of 35 and 49 (6%); ? within Amsterdam and some cities in the neighbourhood (6% and more).
Figures of accidents combined with the percentages of drink driving show that there is a much higher risk of getting involved in an accident while under the influence of alcohol.
Young male car drivers (18-25-year-olds) are a special risk group. The quantity of alcohol consumed, combined with the small amount of driving experience, annually causes approximately 25% of all fatal alcohol-related accidents in the Netherlands.
Therefore, a supplementary study was launched from 2002 in connection with the introduction of the beginners? driving licence. In 2004, drivers with a Blood Alcohol Content (BAC) in the 0.2-0.5? range will be in violation of the law if they have held their drivers? licence for less than five years. About 80 % of them are between 18 and 25 year old. In 2001, a total of 4.1% of young drivers had a BAC in the aforementioned range (0.2 ? 0.5?). 87 % of them are men.
Furthermore, at the end of 2001, the ?Bob? campaign has started in the Netherlands. In this campaign Bob is the one who does not drink and drives his (or her) friends home.
With the use of figures of 2002, there will be investigated if there can be measured an effect on the percentage of drink driving. To find such an effect is uncertain, due to a lot of confounding factors, which can vary in the same period. However, the main factors that lead to changes in the percentage of drink drivers and their effects are approximately known from earlier studies.
Association for European Transport