Best practice in random breath testing and cost-effective intensity levels

Background Random breath testing (RBT) aimed at general deterrence of drink-driving has been shown to be more effective than targeted alcohol screening from patrol cars aimed at apprehending drink-drivers. The European PEPPER study’s meta-analysis of 40 evaluations found that the largest crash reductions were achieved by Australian methods of RBT (involving use of highvisibility bus-based testing stations as well as car-based operations and supported by massmedia publicity) compared with other countries. Aim This paper aims to summarise the characteristics of Australian RBT that make it best practice. Method Extensive research has been conducted since RBT was first introduced in Victoria in July 1976 and subsequently in other States. Research linking the intensity of RBT with reductions in serious alcohol-related crashes is summarised in the paper. Results General deterrence through the perceived risk of detection is maximised by operations that appear to cover broad areas and both minor and major roads, achieve at least 20 hours per 100 square kilometres per week in urban areas, are highly visible and test a substantial proportion of passing motorists. Car-based RBT should be preferred in rural areas, covering also minor roads that may be used in evasion strategies, and bus-based RBT stations should only be operated in conjunction with car-based RBT placed on alternative roads. Diminishing-returns type relationships between the intensity of RBT and reductions in serious alcohol-related crashes have been calibrated. It was found that breath testing rates per licensed driver could be increased to at least 1.5 per year before cost-effectiveness is in doubt. Discussion and conclusions RBT is remarkably effective in providing general deterrence of drink-driving and should be preferred over operations aimed principally at apprehending drink-drivers. Characteristics of RBT operations that maximise effectiveness have been identified. While labour-intensive, RBT is so effective that testing rates per licensed driver can be increased to high levels and still justify their cost by the savings in road trauma. Background and effectiveness of different methods of drink driving enforcement There are many studies indicating the effectiveness of random breath testing in reducing fatal and serious injury crashes, especially those crashes likely to involve illegal BAC. Erke et al (2009) conducted a meta-analysis of 40 good quality studies and found that crashes involving alcohol were reduced by 17% at a minimum and that all crashes, independent of alcohol involvement, were reduced by about 10–15%. Larger crash reductions were found due to Australian methods of RBT (involving use of high-visibility bus-based testing and supported by mass media publicity) compared with alcohol checkpoints in other countries.