Public Health and Safety

Fatal Crashes: Marijuana’s involvement doubles from 2000 – 2018

The rate of fatal motor vehicle crashes, involving only marijuana or marijuana with alcohol has doubled from 2000 to 2018. During this same time, many states legalized marijuana, first for medical use and later for commercial adult use. 

In a recent peer reviewed study published in the American Journal of Public Health (AJPH November 2021, Vol 111, No. 11) the authors (Lira examined longitudinal data concerning fatal motor vehicle crashes in America, from 2000 – 2018, and the detected presence of marijuana alone and marijuana in conjunction with alcohol in those cases. The source of this data was the Fatality Analysis Reporting System (FARS), part of the National Highway Transportation and Safety Administration (NHTSA). The FARS database is populated nationally by traffic reports submitted by law enforcement and subsequent toxicology reports for drug testing. During this time there were over 721,000 fatal traffic crashes. 

Upon review of the fatal crash data, the authors noted that the trend for “alcohol only” involvement remained “stable”. However, upon looking at marijuana’s involvement, the authors noted an increase in the presence of detectable levels of marijuana in these fatality cases. Specifically, for marijuana alone, from 2000 – 2018, the involvement rate increased (138%) from 9% to 21.5%. For marijuana in combination with alcohol for the same time frame, the rate increased (114%) from 4.8% to 10.3%. 

Numerous studies cite that marijuana is the most frequently detected illicit drug detected in fatal car crashes, along with alcohol. Emerging public safety studies have noted that both alcohol and the THC found in marijuana do cause impairment to a driver’s ability to safely operate a motor vehicle. The authors note that more research is needed to fully understand the synergistic effects that marijuana and marijuana in conjunction with alcohol has on drivers.  

The report offers an excellent foundation to examine the public health and public safety impacts represented by marijuana’s increasing prevalence in matters of highway safety. 

Read Time: 10-15 minutes

Photo: / J. Santos