Cannabis users living in adult-use states are less likely to drive while stoned than those living in prohibition states, according to a recent study published in the journal Preventive Medicine Reports.
Researchers from the Center for Health Analytics, Media, and Policy at RTI International analyzed data from a national sample of 1,249 people who had used cannabis within the past 30 days. The survey, which was conducted between 2016 and 2017, asked subjects to anonymously report whether they had driven a car within three hours of getting high, among other questions.
The study authors then compared the rates of self-reported stoned driving by people who lived in adult-use states with those who lived in prohibition states. Contrary to anti-legalization rhetoric, they found that residents of adult-use states were actually less likely to drive under the influence of pot than those who didn't. Frequent cannabis users living in medical marijuana states were just as likely to drive stoned as those living in prohibition states, however.
“The risk of self-reported DUIC [driving under the influence of cannabis] was lower in recreational and medical cannabis states compared to states without legal cannabis,” the study authors wrote. “The only exception was for frequent users in medical states, for whom there was no difference in risk compared to frequent users living in states without legal cannabis.”
Researchers suggested that the difference may be due to the fact that every adult-use state has launched educational programs warning about the risk of stoned driving. Legal cannabis products also include specific warnings against driving under the influence, unlike weed obtained via the black market. Additionally, many of these states have also increased funding for highway patrols targeted at identifying weed-impaired drivers, which may further discourage DUIC.
The research does have one important limitation. Since the study relies entirely on self-reports, it's possible that some subjects were not completely honest about how often they drove while stoned. The study authors are confident that their research methods would have detected “underreporting of DUIC,” however. And even if some subjects were less than honest, it is still evident that residents of adult-use states are more aware of the risks of driving under the influence than those who live elsewhere.
“Although all states should educate [their] citizens about the potential dangers of using cannabis and driving, this analysis suggests that states without legal cannabis are particularly in need of DUIC prevention efforts,” the study concludes. “Our analysis also suggests that frequent users in states with medical legalization or no legal cannabis may be at particular risk for DUIC. States should consider mass media campaigns as a method of reaching all cannabis users, including more frequent users, with information about the dangers of DUIC.”
Previous studies have also suggested that fears about legalization and traffic accidents are unwarranted. Some researchers have found that recent THC use can lead to an increased likelihood of weaving, but other studies have found no link between THC and increased rates of traffic accidents. Other recent studies report that regular cannabis users drive as safely as sober drivers, and that driving while stoned is far safer than driving under the influence of opioids, Xanax, or other perfectly legal prescription drugs.
“These findings ought to reassure those who feared that legalization might inadvertently be associated with relaxed attitudes toward driving under the influence,” said NORML Deputy Director Paul Armentano in a statement. “These conclusions show that this has not been the case and that, in fact, consumers residing in legal marijuana states are less likely to engage in this behavior than are those residing in states where cannabis possession remains criminalized.”