Alcohol is a drug that is recognized as a risk factor for many categories of unintentional injury (Smith, Branas, & Miller, 1999; Skog, 2001). In 2006, 17,602 people were killed in the United States (U.S.) in alcohol-related crashes where at least one driver, pedestrian or cyclist had a blood alcohol content (BAC) of 0.01 g/dl or over (National Highway Tra¬c Safety Administration (NHTSA, 2007). šis represents 41.3% of all motor-vehicle crash

fatalities for 2006. še number of people killed in alcohol-related crashes where at least one driver or motorcycle operator had a BAC over the U.S. legal limit of 0.08 g/dl was 13,470 (NHTSA, 2008). Of those 13,470 fatalities, 64% were the impaired drivers, 18% were passengers riding with the impaired driver, 11.9% were occupants of other vehicles, and 6.1% were non-occupants (NHTSA, 2008). In 2000, alcohol-involved crashes accounted for $50.9 billion (22%) of the $230.6 billion cost associated with motor vehicle crashes (Blincoe et al., 2002). Given the high

incidence and associated cost of alcohol crashes, NHTSA has identi¨ed the reduction of alcohol-related tra¬c fatalities as a priority for improving tra¬c safety (NHTSA, 2001).