Young men and women aged 18 - 24 years travel very frequently in motor vehicles at night, both on weekdays and at the weekends. In approximately half of these cases, the driver is accompanied by passengers. Such trips are usually recreational, made with the aim of "having a good time" or "being with others". Journeys with more than one person in the vehicle made at the weekends frequently include members of both sexes; those made on weekday evenings more often include only members of the same sex. The study of alcohol consumption shows that the amount of alcohol consumed increases significantly both for males and females between the ages of 18 and 24 years. Taking into consideration the fact that people in this age-group frequently consume alcohol during the evenings and in public places rather than at home, it becomes clear to what extent young drivers are subjected to the drink-drive conflict. Risk analysis shows that the presence of passengers generally reduces the risk of accident; a journey with two people in the vehicle has a 15 % lower accident risk than when the driver is alone; a journey with more than one passenger reduces the risk by 8 %. This passenger effect is considerably larger for female than for male drivers. The risk that a female driver has an accident is 31 % smaller when she has one passenger than when she drives alone and 20% smaller when she has more than one passenger. However, this general effect does not apply in the case of young drivers. For this group, the number of people in the vehicle makes no significant difference to the accident risk. Observation studies at intersections, analysis of speeding and experimental testing of the passenger effect suggest the same as do the accident analyses: drivers tend to drive more slowly when carrying passengers. However, passengers no longer have this protective effect when the driver is confronted with a difficult traffic situation where many demands are made on him. Passengers have an indirect effect on driving safety by diverting the drivers attention from the actual task of driving. The driver compensates for this by making the driving process less demanding for himself, in particular by reducing his speed. The level of driving difficulty and the readiness of the driver to compensate are therefore prerequisites for the protective effect caused by the presence of passengers. This also explains why driving with a blood alcohol concentration of over 80 mg/100 ml and accompanied by a passenger is 2.5 times as dangerous as driving alone and why the accident risk of young drivers under the influence of alcohol is independent of the number of passengers. In both cases, the influence of the alcohol raises the level of driving difficulty. Moreover, the readiness to compensate decreases under the influence of alcohol ("loss of inhibitions"); it is also less pronounced in young drivers. Safety work concerning young drivers should therefore be extended to include their social environment. Preventive work should include explaining to drivers the effects of passengers and that contact should be restricted to times when the driver has reserves of attention which he can utilise and he is able to compensate by driving in a different manner. However, it should also be ensured that passengers are familiar with the effects of communication on driving safety and that they behave accordingly. (Author/publisher)
Samenvatting