Background Alcohol-impaired driving crashes claim about 13 000 lives each year in the United States.

Objective We estimated the prevalence of alcohol-impaired driving (AID) among adults using 2006 and 2008 data from the Behavioural Risk Factor Surveillance System (BRFSS).

Methods AID was assessed by asking, during the past 30 days, that is since ____, how many times have you driven when you perhaps had too much to drink? Annualised weighted estimates and rates of AID episodes were calculated for the United States and by state.

Results Of the 754 539 BRFSS respondents in 2006 and 2008, 1.1% of women and 3.4% of men reported at least one AID episode in the past 30 days. The annualised national rate of AID episodes was 646 per 1000 population. Men aged 18–24 years, who make up 7% of the total adult population, accounted for 27% of all AID episodes. Annualised AID rates varied more than sevenfold across states, from 165 per 1000 population in Utah to 1242 per 1000 population in Iowa. States in midsection generally had higher AID rates than those in the south and northeast.

Conclusions Alcohol-impaired driving remains prevalent. These results can aid states in monitoring trends in AID and intervening with groups at greater risk for AID.