Road safety impact of extended drinking hours in Ontario.

PURPOSE On 1 May 1996, Ontario, Canada amended the Liquor Licence Act to extend the hours of alcohol sales and service in licensed establishments from 1 to 2 a.m. The purpose of this study was to evaluate the road safety impact of extended drinking hours in Ontario. METHOD A quasi-experimental design using interrupted time series with a nonequivalent no-intervention control group was used to assess changes. The analyzed data sets are total and alcohol-related, monthly, traffic fatalities for Ontario, for the 11-12 p.m., 12-1 a.m., 1-2 a.m. and 2-3 a.m. time windows, for Sunday through Wednesday nights and for Thursday through Saturday nights, for 4 years pre- and 3 years post-policy change, compared to neighbouring regions of New York and Michigan. RESULTS The blood alcohol concentration positive driver fatality trends reflected downward trends for Sunday-Wednesday 12-2 a.m. and Thursday-Saturday 1-2 a.m. for Ontario and downward trends for Thursday-Saturday 12-1 a.m. and 2-3 a.m. for New York and Michigan after the extended drinking hour policy change. Ontario total fatality data showed similar trends to the Ontario blood alcohol positive trends. CONCLUSIONS The multiple datasets converge in suggesting little impact on BAC positive fatalities with extension of the closing hours. These observations are consistent with other studies of small changes in alcohol availability.