Random breath testing as a deterrent to drinking drivers

Legislation which allows police randomly to select drivers for breath testing is in operation in Australia and in northern ireland. The laws are seen to act as deterrents to drink driving behaviour by increasing the threat of detection perceived by potential offenders. In this paper we compare the risks of encountering a random breath testing station as perceived by drivers in Melbourne, Australia, and in belfast, northern ireland, at different times of the year. We show that the level of this perceived risk among night time, weekend drivers is unrelated to the frequency of alcohol use; we look at the influence of the media in increasing the deterrent value of the law (a).