Driving Under the Influence of Cannabis: A Framework for Future Policy

Abstract

Marijuana is the most widely consumed illicit substance in the United States, and an increasing number of states have legalized it for both medicinal and recreational purposes. As it becomes more readily available, there will be a concurrent rise in the number of users and, consequently, the number of motor vehicle operators driving under the influence. This article examines the cognitive and psychomotor effects of cannabis, as well as current policy concerning driving under the influence of drugs. The authors performed a MEDLINE search on the epidemiology of cannabis use, its cognitive and psychomotor effects, and policies regarding driving under the influence of drugs. Twenty-eight epidemiological studies, 16 acute cognitive and psychomotor studies, 8 chronic cognitive and psychomotor studies, and pertinent state and federal laws and policies were reviewed. These search results revealed that marijuana use is associated with significant cognitive and psychomotor effects. In addition, the legalization of marijuana varies from state to state, as do the laws pertaining to driving under the influence of drugs. Marijuana is a commonly found illicit substance in motor vehicle operators driving under the influence of drugs. Current evidence shows that blood levels of tetrahydrocannabinol do not correlate well with the level of impairment. In addition, although acute infrequent use of cannabis typically leads to cognitive and psychomotor impairment, this is not consistently the case for chronic heavy use. To establish the framework for driving under the influence of cannabis policy, we must review the current published evidence and examine existing policy at state and federal levels.

Societal issues and policy implications related to the use of cannabinoids, cannabis, and cannabis-based medicines for pain management

“…Systematic reviews show consistent evidence that use of cannabis impairs cognitive and psychomotor ability and impairs driving skill. 15 Effects are mainly acute but can last for 24 hours. This is consistent with an association between acute cannabis consumption and an approximate doubling in risk of motor vehicle collision.…”

Sex differences in driving under the influence of cannabis: The role of medical and recreational cannabis use

“…Furthermore, the effects of cannabis can be influenced by frequency of use, age of initiation, and co-use with other substances. For instance, infrequent users have been shown to experience greater impairment than users who have a tolerance for cannabis (Chow et al, 2019;Desrosiers et al, 2015). Moreover, Dahlgren and colleagues (2020) determined that even without acute intoxication, chronic, heavy recreational cannabis users had decreased driving performance compared to healthy controls, including increased accidents, speed, lateral movement, and decreased rulefollowing.…”

Are Current Drug Driving Enforcement Strategies Achieving the Desired Effect? Drug Users’ Perceptions of Drug Driving Legislation and Enforcement in Queensland

“…A final factor that emerged among participants' responses to improve perceptions of current testing was that of adopting field sobriety testing approach of suspected drug drivers (R45), or a more detailed approach to drug driving on medical cannabis specifically (R46). Given the inconsistent relationship between THC presence and impairment (Chow et al 2019), a number of countries have adopted the use of roadside field sobriety tests to judge impairment among suspected cannabis drivers. While a valid and efficient behavioural test of impairment may address some possible issues associated with the interviewees' perceptions of current police methods, there are some major limitations to this approach (particularly within Australian jurisdictions), as recently evaluated by Spindle et al (2021).…”