Regular alcohol checks are effective in reducing the number of alcohol-related crashes. A meta-analysis on results from forty studies indicates that crashes decrease by 17% when regular alcohol checks are carried out [75]. The effects are considerably larger in Australia (22% reduction) than in the United States (12% reduction).
The greater effectiveness in Australia is probably due to the fact that they use random breath testing on large numbers of drivers (annually, about one in three is tested ). In random testing, every stopped driver is tested for alcohol use, irrespective of gender, age, or skin colour. In the United States, considerably fewer drivers are tested for alcohol and testing is not random. According to the law, a police officer can only carry out a breath test if a driver is suspected to be under the influence.
Partly based on Dutch data, Mathijssen [63] estimated that each doubling of the number of alcohol checks results in 25% fewer alcohol offenders.
