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%.
Samenvatting