Driving After Drug or Alcohol Use: Findings from the 1996 National Household Survey on Drug Abuse

Abstract

This report contains findings from questions included in the 1996 National Household Survey on Drug Abuse (NHSDA). The data presented describe the prevalence and patterns of driving following drug use and/or alcohol use by 11,847 NHSDA respondents, representing over 166 million drivers age 16 and older in the United States. The analysis was limited to those age 16 and older who reported driving in the past year and answered the question on whether or they drove within two hours after substance use. Five percent of drivers, representing approximately 8.9 million people, reported driving within two hours of drug use, with or without alcohol, in the past year. An additional 23 percent of drivers, representing approximately 39 million people, reported driving after alcohol use only. The data revealed that compared to those who reported drinking and driving, those who reported driving after drug use were generally younger (i.e., age 16-20) and more likely to be single, unemployed, have a lower annual personal income, and to have been on probation during the past year. More detailed data reveal that driving following marijuana use most commonly occurred on smaller roads, in urban areas, on weekends and began between 6:00pm and 11:59pm. The most commonly reported reasons for driving following marijuana use were that the drivers no other way to get there and felt they were not high enough to cause a crash. In fact, these drivers generally felt that marijuana did affect their ability to drive safely or their likelihood of being stopped by the police. Finally, estimated blood alcohol concentration (BAC) levels were used as an indicator of level of impairment for those who drove following alcohol use. Drivers age 16-20 were more likely than drivers age 21 and older to have higher estimated BAC levels and female drivers over age 25 had higher average BAC levels than males of the same age.