Characteristics of Designated Drivers and Their Passengers From the 2007 National Roadside Survey in the United States

Objective: The objectives of this study were to estimate the prevalence of designated driving in the United States, compare these results with those from the 1996 National Roadside Survey, and explore the demographic, drinking, and trip characteristics of both designated drivers and their passengers. Methods: The data used were from the 2007 National Roadside Survey, which randomly stopped drivers, administered breath tests for alcohol, and administered a questionnaire to drivers and front seat passengers. Results: Almost a third (30%) of nighttime drivers reported being designated drivers, with 84 percent of them having a blood alcohol concentration of zero. Drivers who were more likely to be designated drivers were those with a blood alcohol concentration that was over zero but still legal; who were under 35 years of age; who were African American, Hispanic, or Asian; and whose driving trip originated at a bar, tavern, or club. Over a third of passengers of designated drivers reported consuming an alcoholic drink the day of the survey compared to a fifth of passengers of nondesignated drivers. One fifth of passengers of designated drivers who reported drinking consumed 5 or more drinks that day. Conclusions: Designated driving is widely used in the United States, with the majority of designated drivers abstaining from drinking alcohol. However, because designated driving separates drinking from driving for passengers in a group traveling together, this may encourage passengers to binge drink, which is associated with many adverse health consequences in addition to those arising from alcohol-impaired driving. Designated driving programs and campaigns, although not proven to be effective when used alone, can complement proven effective interventions to help reduce excessive drinking and alcohol-impaired driving.