CMCR Co-Director Tom Marcotte, PhD, collaborated with Linda Hill, MD, MPH and researchers from UC San Diego’s Herbert Wertheim School of Public Health and Human Longevity Science on a new study examining how cannabis users respond to public safety messages about cannabis-impaired driving.
Published in Traffic Injury Prevention, the study surveyed 846 adults from eight U.S. states who had recently used cannabis, drove at least weekly, and believed it was safe to drive on the same day as cannabis use. Participants reviewed prevention messages and rated them on attention, appeal, relevance, believability, offensiveness, and likelihood of influencing safer behaviors.
Messages emphasizing concrete impairment effects, such as “Feel Different, Drive Different” and “THC slows reaction time,” generally performed best. Participants viewed clear, factual, evidence-based messages as more credible than messages perceived as exaggerated, fear-based, stigmatizing, or punitive.
The study also found that messaging was more likely to encourage harm-reduction behaviors, such as waiting longer before driving, staying in the same location, or using alternative transportation, than to reduce cannabis use overall. Medium- and high-risk drivers appeared more responsive to messaging than ultra-high-risk drivers, suggesting that people most likely to drive soon after cannabis use may need more tailored or intensive approaches.
Healthcare providers and science-based organizations were among the most trusted messengers, while celebrities and social media influencers were rated least trustworthy.
Overall, the findings support cannabis-impaired driving campaigns that are clear, credible, nonjudgmental, and tailored to different driver risk profiles.