Prevalence of alcohol, cannabis, and simultaneous use among drivers in six states

November 2023

Objective: As more states legalize cannabis for recreational use, there is a need to understand how cannabis is used with other substances. Combining alcohol and cannabis at the same time is of particular concern, as this combination has been found to worsen driving performance and is associated with riskier behaviors. Method: Telephone interviews were conducted with 3045 adult drivers across six states (Connecticut, Delaware, New York, North Carolina, South Carolina, and Virginia) about their opinions and behaviors related to cannabis use, alcohol use, and driving. Results:The prevalence of past-year drinking ranged from 65% in North Carolina to 75% in New York and Connecticut, past-year cannabis use ranged from 21% in North Carolina and Virginia to 29% in New York, and simultaneous use ranged from 9% in North Carolina to 15% in New York. Across the six states, a large majority of drivers agreed drinking alcohol before driving increases crash risk (95%–97%), whereas agreement about whether cannabis use increases crash risk ranged from 63% in North Carolina to 73% in New York. Substance use less than 2 hours before driving was more prevalent for alcohol (17%–25%) than for cannabis (8%–11%) or both substances (2%–5%). Conclusions: Because of the heightened risks associated with the use of alcohol and cannabis together, self-report surveys should include questions about simultaneous use of alcohol and cannabis in addition to questions about individual substances. An understanding of how substances are used either alone or in combination can better inform traffic safety programs.