Legalization of Marijuana in US States Linked to Rise in Fatal Car Accidents

People handle the aftermath of a car accident in a file photo in Irvine, Calif., on March 30, 2022. (John Fredricks/The Epoch Times)

Several U.S. states which legalized marijuana use have seen a spike in car accidents and traffic-related deaths, according to a recent study.

Researchers have linked an increase of 22 percent in fatal road crashes in certain states to the legalization of cannabis, according to a new study by the University of Illinois Chicago School of Public Health.

The UIC team led by Samantha Marinello reviewed death certificate data to compare mortality rates in states that had legalized cannabis for recreational use to those which had longstanding medical cannabis programs, while looking at similar trends in death rates prior to authorization of the drug in those markets.

“We didn’t want to compare states with very different mortality trends or social ideology, so we looked at each state and outcome and identified comparison states with existing medical cannabis programs and with similar pre-trends to conduct our analysis,” Marinello said.

They found that fatal road accidents had escalated dramatically in four of those states that allowed recreational marijuana.

Recreational markets were associated, on average, with a 10 percent increase in fatal motor vehicle accidents.

The report “The impact of recreational cannabis markets on motor vehicle accident, suicide, and opioid overdose fatalities” was published in March in the ScienceDirect journal of Social Science & Medicine, while another study published in 2022 in the Journal of Studies on Alcohol and Drugs found similar results.

Cannabis Causes Increase in Traffic Accidents

The data covered the period from 2009 to 2019, focusing on three fatal categories previously associated with cannabis use, but required further research, such as motor vehicle accidents, suicide, and opioid overdoses.

“To see a 10 percent increase in motor vehicle accident deaths associated with recreational markets is concerning,” said Marinello, a postdoctoral research associate with the Division of Health Policy and Administration at the UIC School of Public Health, in a March 2023 press statement.

“Previous studies have found cannabis impairs driving ability and that driving while high is fairly common among regular cannabis users,” she said.

The seven states investigated in the study were Alaska, California, Colorado, Massachusetts, Nevada, Oregon, and Washington.

The data showed a significant spike in crash fatalities in Colorado (16 percent), Oregon (22 percent), Alaska (20 percent), and California (14 percent).

“The results suggest that a potential unintended consequence of recreational markets is increased cannabis-intoxicated driving and crash deaths, and, hence, a potential need for policies focused on reducing driving under the influence of cannabis,” noted Marinello.

However, states that legalized recreational cannabis saw an 11 percent average reduction in fatalities due to opioid overdoses in comparison, but the decline varied from three to 28 percent across those seven states.

Marinello added that the reduction in opioid overdose fatalities due to marijuana legalization is something that should be seriously reviewed in states considering legalization.

“This study provides evidence of both potential benefits and harms that policymakers should consider when legalizing recreational cannabis markets,” she continued.

Surprisingly, the researchers found no evidence that marijuana legalization had an impact on suicides rates, which is interesting, as cannabis use is long associated with the development of depressive disorders and suicidal thoughts.

The UIC team concluded that it would be a good idea for states that fully legalized cannabis use to promote policies and public health programs that would help curb the potential harm caused by these substances, as well as inform the public that driving under the influence of marijuana can be deadly.

Other Marijuana Studies Confirm Results

Meanwhile, the 2022 study also found strong evidence that marijuana legalization in the United States led to upticks in severe car crashes.

The team collected data on traffic crashes and the amount of traffic in 11 U.S. states and from the Federal Highway Administration between 2009 and 2019.

Colorado, Washington, Oregon, California, and Nevada had all legalized recreational marijuana during the period, while Arizona, Idaho, Montana, New Mexico, Utah, and Wyoming did not.

The report found that the number of crashes, which led to injury, surged by about six percent in states with legalized marijuana, while the number of fatal crashes jumped by four percent in five states that permitted recreational use.

Nonetheless, the researchers did not see a spike in a comparison group of six states that have not legalized the drug.

The number of fatal crashes rose by around two percent after cannabis was legalized and again by the same amount when shops started selling the drug.

Crashes leading to injury rose overall, by 6.5 percent after legalization, but fell slightly once marijuana sales were legalized in stores.

Researchers from the University of California-San Francisco in 2019, reviewed over 28 million hospital records from before and after recreational cannabis was legalized in Colorado in December 2012.

The UCSF team reported that hospital admissions related to cannabis use had jumped 10 percent post-legalization in Colorado compared to other states, but found that there was not a significant increase when taking all admissions and time spent in hospitals into account.

The results also showed a 5 percent jump in alcohol abuse and overdoses that resulted in injury or death and 5 percent fewer hospitalizations for chronic pain after marijuana legalization.