In 1998, the Belgian Road Safety Institute (BIVV-IBSR) conducted for the first time a roadside survey on drinking and driving. Drivers were stopped randomly and were provided with a breath alcohol test. Furthermore, information such as sex, age, ... of the drivers was gathered. The roadside survey was realised in co-operation with the local and federal police forces. There are two main differences between the selective way in which police forces in Belgium usually work and the a-selective way in which the roadside survey was conducted. Firstly, since every stopped driver is tested, it is impossible that impaired drivers remain undetected. Secondly, the group of drivers selected at random can be seen as a non-biassed representation of the population. Thus, inferential statistics can be used to assess a measure for the population. The BIVV-IBSR has several goals in organising the roadside survey. Scientific research shows that random breath testing, if coincided with an information campaign highlighting the visibility and enlarging the consciousness about the police check, has a bigger general deterrence effect. Logically this should result in a lower percentage of drunk drivers and alcohol related accidents. Furthermore, the results of the roadside survey make it possible to assess the proportion of drink driving in Belgium and to describe the profile of the drunk driver. Repetition of the survey gives some idea of the evolution of the proportion and the profile. This information, in combination with data from alcohol related accidents, can support the policy to diminish the drink-driving problem in Belgium. Finally, the drink-driving evolution reflects the evolution of alcohol related accidents. Since accident data is not always available or the numbers are too limited to be reliable, results of a roadside survey can be used as an indirect measure to evaluate the alcohol related accident reduction. In this discussion paper, we emphasise some recommendations to support effective police checks in traffic. To clarify why we do so, we firstly summarise literature about random breath testing and we discuss the results of our own research. Police activities in traffic must imply more than just verbalising in a rather arbitrary way. Ideally, traffic control activities are based on a smart plan, which results from common knowledge about police checks in traffic on the one hand and from specific knowledge about the local situation on the other hand. Common knowledge about police checks in traffic implies deterrence theory, which says that a sophisticated equilibrium between objective and subjective risk of detection is the key to success. Specific knowledge about the local situation indicates that the proportion of drink driving in Belgium - i.e. driving while having a breath alcohol concentration (BAC) of more than 0,22 milligrams alcohol per litre exhaled air - is 8,8% ± 0,5%. A significant difference was found between the regions: in the southern region of Belgium (the Walloon provinces) 10,1% ± 0,9% of all drivers were impaired, while in the northern region (Flanders) and the central region (Brussels) only 8,4% ± 0,6% and 6,5% ± 1,4% of the drivers were drink driving. The loglinear analysis for the national level shows that the drunk driver was mainly a male, aged minimum 26 but not older than 54, and who transported no passengers. Despite the finding that impaired drivers mainly had consumed beverages in catering establishments (66%), a lot of offenders drank at home, with family or friends (24%). No association between the place where beverages were consumed and BAC-Level could be detected. This means that drunk drivers coming from catering establishments do not systematically drink more or less than those coming from their homes, families or friends. No significant different profiles between the regions or the provinces could be detected, except the place where beverages were consumed. Recommendations based on common knowledge consist, on the one hand, of those to optimise the equilibrium between the objective and the subjective detection risk, and, on the other hand, of those to optimise the practical organisation of police checks in traffic. Finally, we make some recommendations based on our specific knowledge about the local situation. (A)
Samenvatting