The Effects of Blood Alcohol Levels on Driving Variables in a High-Risk Population: Objective and Subjective Measures

Alcohol intoxication is a major cause of automobile crashes. In order to reduce such accidents, individuals must be able to recognize their intoxication, determine that they cannot drive safety and then decide not to drive. Whether individuals are able to make such choices, either before or after they get behind the wheel, is unclear. This study assessed highrisk individuals' subjective awareness of legal intoxication (blood alcohol levels of ≥ 0.10%) and ability to drive, and objectively quantified their blood alcohol levels (BALs) and driving performance, using a repeated measures cross-over (placebo and alcohol) design. While subjects were able to recognize legal intoxication, one third of the subjects were still willing to drive after the drinking experience may in part be due to the fact that legal intoxication did not grossly disrupt routinized driving performance, possibly providing a false sense of security.