The 2013-2014 National Roadside Study of Alcohol and Drug Use presents national prevalence estimates for alcohol and other drug use among drivers.

Drugs studied included over-the-counter, prescription, and illegal substances. Drivers were randomly selected at 60 sites (300 locations) across the continental United States. Data were collected during one 2-hour Friday daytime session (either 9:30-11:30 a.m. or 1:30-3:30 p.m.) and four 2-hour nighttime periods (10 p.m.-midnight and 1-3 a.m. on both Friday and Saturday nights). Participation was voluntary and anonymous.

This study also compared results to those of the 2007 National Roadside Survey. This study (and the 2007 study) estimated drug prevalence. A positive result for a drug does not necessarily mean the driver was impaired at the time of testing, only that the drug was present in the body. Data from these studies cannot be used to draw conclusions about drug-impaired driving.

There are 3 reports in this series. Volume 1 describes the methodology, Volume 2 presents the alcohol results, and Volume 3 presents the drug results.

• Volume I: Methodology
• Volume II: Alcohol Results
• Volume III: Drug Results
• Research Note