EFFECTS OF A REDUCED ALCOHOL LIMIT FOR DRIVING

Data from random breath testing (RBT) by police, and blood alcohol content (BAC) tests of drivers involved in crashes, were used to assess the effects of a reduction in the legal BAC limit for driving. On 1 January 1991, the limit was reduced from 0.08% to 0.05% in the Australian Capital Territory (ACT), but penalties for drinking with BAC over 0.08% were not changed. Results from the study support the hypothesis that one of the major benefits of a lower BAC limit may be a decision to reduce drink-driving at very high levels, well above the legal limit. RBT results for 1991 showed that there was 41% less incidence of drink-driving at BAC above 0.15%, compared with 1990, and a reduction of about 90% in drink-driving at BAC between 0.05% and 0.08%. The observed small reduction in drink-driving at BAC between 0.10% and 0.15% was not statistically significant. Monthly RBT data showed a sharp reduction of drink-driving in January 1991, with no evidence of reversion for former drink-driving patterns during 1991. Post-crash data showed 35% fewer drivers with BAC above 0.10%. For the covering abstract, see IRRD 866577.