The failure of feedback on alcohol impairment to reduce impaired driving.

We examined the effects of rules to govern drinking, individual feedback on blood alcohol concentration (BAC), and public posting of group data on impaired driving on the incidence of impaired driving. Level of impairment was determined from breath samples taken from tavern patrons. Following baseline, an intervention package consisting of (a) cards to guide patrons in pacing their drinking to stay under the legal limit, (b) individual feedback on BAC, and (c) posted group feedback on the percentage of patrons driving while impaired the preceding week was introduced in two taverns. Results indicated that the intervention package did not reduce the percentage of impaired drivers departing either tavern. The addition of a brief intensive police enforcement program directed at impaired driving produced a short-term reduction in impaired driving.