The establishment of licensed cannabis retailers is not independently associated with an increase in traffic crashes, according to data published in the journal Health Economics.
A researcher affiliated with the University of California, San Diego examined county-level data from Colorado to assess the relationship between retail cannabis stores and trends in traffic safety.
The investigator reported, “[T]he entry of retail cannabis stores is not associated with a statistically significant change in traffic crashes per 100,000 population in Colorado.”
He concluded: “The findings of a lack of relationship between expanding access to marijuana through retail stores and traffic crash[ees] may seem counterintuitive, especially since the use of marijuana has been linked to lower neuromotor/neurocognitive performance required to drive safely and a higher risk of being involved in a traffic crash. However, recent studies have found evidence of substitutability between marijuana and other substances that can impair driving performance, such as alcohol. In this case, the net effect of expanding access to marijuana on traffic crashes could be quite small. The findings of this study are consistent with this hypothesis.”
Several prior studies have assessed whether the enactment of adult-use legalization is associated with an increased risk in the likelihood of motor vehicle accidents. The findings of those studies have yielded inconsistent results, with some studies identifying a minor uptick in crash rates in specific states several years following legalization, and others finding no such change.
Full text of the study, “Does expanding access to cannabis affect traffic crashes? County-level evidence from recreational marijuana dispensary sales in Colorado,” appears in Health Economics. Additional information on cannabis, psychomotor performance, and accident risk is available from the NORML fact sheet, “Marijuana and Psychomotor Performance.“