Marijuana use and driving in Washington State: Risk perceptions and behaviors before and after implementation of retail sales.

CONCLUSIONS: The prevalence of daytime THC-positive drivers increased substantially a few months after retail sales of marijuana were legal. Daytime and nighttime prevalence of THC-positive drivers was similar after retail sales. This pattern differs from that typically found for alcohol use, which is consistently higher among drivers at nighttime, compared to daytime. Reports of marijuana use were not always consistent with drug test results, which suggests that comparisons of self-reported marijuana use before and after legalization could be biased. This study examined marijuana use and risk perceptions over the course of 1 year. However, law changes may influence cultural norms gradually over a longer period of time. Future studies should continue to monitor marijuana use over time, as well as identify ways to determine whether drivers are impaired by marijuana. PMID: 30822133 [PubMed - as supplied by publisher]
Source: Traffic Injury Prevention - Category: Accident Prevention Authors: Tags: Traffic Inj Prev Source Type: research