Publicity, police resources and the effectiveness of random breath testing

Random breath testing (RBT) of drivers by the police was introduced in South Australia in 1981 at a very low level of enforcement. As there was no lasting effect on illegal "drink driving" the resources devoted to RBT were increased in 1987. In the months after this change police doubled the number of drivers tested by RBT. Concurrent with this change in the level of enforcement of RBT was an extensive publicity campaign, which warned drinking drivers of their increased risk of detection by RBT units. A roadside breath alcohol survey, conducted in metropolitan Adelaide late at night to evaluate the effect of these changes, showed a 34% reduction in the proportion of car drivers detected with a blood alcohol concentration at or above the legal limit of 0.08 g/100 mL.