Drinking and Driving

The most direct way of measuring the prevalence of drinking and driving is to take breath tests from a random sample of motorists. A number of countries carry out these surveys periodically, usually at nights and at weekends when drinking drivers are more numerous. Two groups of nations emerge in these studies. One group includes Scandinavia and Australia, where there are relatively few drinking drivers on the roads. Moderate to high BACs are found among less than 1 percent of drivers in these countries, even at peak leisure times. The second group includes the United States, Canada, France, and the Netherlands, where between 5 and 10 percent of drivers during nighttime leisure hours have moderate to high BACs. These patterns are broadly consistent with overall road fatality rates for different countries, and also with analyses of the BACs of drivers killed. However, in these latter studies even the Scandinavian countries have found that more than a quarter of drivers have positive BACs, despite the low numbers overall of drinking drivers on the road.

A second main way of estimating the prevalence of drinking and driving is to ask random samples of drivers about their behaviors in the recent past. For example, a 1988 study comparing Norwegian, Australian, and American drivers found that 28 percent of Australians, 24 percent of Americans, but only 2 percent of Norwegians admitted to driving in the past year after four or more drinks (Berger et al.). Despite their poor behaviors, 78 percent of the Australians agreed that it was morally wrong to drive after so many drinks, a higher figure than in the United States, but (again) lower than for the Norwegians, who scored a very high 98 percent. Overall, "general prevention," defined as the influence of moral inhibitions and of social pressures, had taken greater hold in Norway than in the English-speaking countries, but general deterrence (behavior change in response to fear of the threat of legal sanctions) was a more potent force in Australia than in the other countries.

Using intoxication among drivers in fatal crashes as an indicator, dramatic reductions in drinking and driving were experienced in most developed countries in the 1980s. However, the indicators reversed direction in the early 1990s, but then continued in modest decline in the second half of the decade. Formal and informal controls on drinking and driving differ markedly from country to country, but nevertheless there appear to be some common influences. Levels of police enforcement (not the severity of penalties) stand out in all countries as an influence, together with a reduction in per capita alcohol consumption. Attention paid to the problem by political leaders, and the visibility of drinking and driving in the press, appear to be critical factors.