Marijuana use is increasingly linked to traffic crashes and injuries in markets where it is legalized, according to recent research.
Alcohol-involved traffic injuries increased by 9.4 percent over the same period.
Canada legalized marijuana—also known as cannabis—for recreational use in 2018. Researchers found that quarterly ED visits for cannabis-involved traffic injuries increased by 94 percent prior to legalization, while this number jumped to 223 percent after legalization.
Currently, 24 U.S. states have legalized recreational cannabis use, as well as Washington D.C., Guam, and the Northern Mariana Islands.
Ohio voters approved a ballot measure for recreational marijuana in 2023, becoming the 24th to legalize non-medical cannabis sales after Minnesota, Virginia, Maryland, Delaware, Missouri, Connecticut, New York, Rhode Island, Vermont, Washington, New Jersey, New Mexico, Montana, Arizona, Maine, Illinois, Michigan, Massachusetts, California, Nevada, Alaska, Oregon, and Colorado.
Florida could become the 25th if the state Supreme Court approves a proposed 2024 ballot measure that would enshrine in its constitution recreational cannabis use for adults over 21.
The effort is backed by Trulieve, the largest marijuana company in Florida and the second-largest in the country.
The ballot measure sponsor, Smart & Safe Florida, gathered more than a million petition signatures by potential voters, surpassing the 891,523 signatures needed to trigger state Supreme Court review.
Cannabis-Impaired Driving
A 2017 study on cannabis and impaired driving in the first two U.S. states to legalize recreational marijuana—Colorado and Washington—found no significant difference between cannabis-related motor vehicle crash fatality rates before and after legalization between 2009 and 2015.The study is not peer-reviewed and the data first reflected an increase in vehicle deaths in states with legal cannabis compared to illegal states between 2016 and 2021.
After deeming the pandemic years of 2020 and 2021 to be too “anomalous” because of a sharp increase in vehicle fatalities across the board, the authors selectively omitted that data and limited the analysis to the years between 2016 and 2019.
After removing the pandemic-era data, the authors concluded that states with legal access to cannabis showed an 11.6 percent decrease in vehicle fatalities during those years while states without access to legal cannabis saw an increase of 1.7 percent.
There was a 5.8 percent increase in injury crash rates and a 4.1 percent increase in fatal crash rates in states that either currently had recreational marijuana retail stores or had recently legalized them.
In some states, legalization of recreational marijuana precedes the opening of retail stores by up to a year or longer.
Not all states saw an increase.
The study notes that injury crash rates ranged from a 7 percent decrease to an 18 percent increase while fatal crash rates ranged from a 10 percent decrease to a 4 percent increase.
The researchers found “a substantial increase in crash fatalities in four of the seven states used in the study with legalized recreational markets and that, on average, recreational markets were associated with a 10 percent increase in motor vehicle accident deaths.”
The seven states featured in the study are Alaska, California, Colorado, Massachusetts, Nevada, Oregon, and Washington.
This data is informative for states like Florida that already have an established medical marijuana industry and may vote in November on expanding into recreational sales.
“To see a 10 percent increase in motor vehicle accident deaths associated with recreational markets is concerning. Previous studies have found cannabis impairs driving ability and that driving while high is fairly common among regular cannabis users,” said study author Samantha Marinello in a news release.
Of the 43,000 motorists who died in vehicle crashes in 2021, 31 percent of those deaths were caused by alcohol-impaired drivers. This is a 14 percent increase from 2020.
Eighteen percent of those fatalities were caused by a “driver who tested positive for two or more impairing drugs.”
The full NCSL report pulled data from the National Highway Traffic Safety Administration (NHTSA).
One NHTSA study looking at trauma center data between October and December 2020 found that 56 percent of motorists who were involved in “serious injury and fatal crashes tested positive for at least one drug.”
That drug is often cannabis.
For Pam Fischer, the senior director of external engagement at the Governors Highway Safety Association (GHSA), the NHTSA data analyzing cannabis impairment and traffic crashes is alarming.
“We know that when you look at other than alcohol, what is the most significant impairing substance they’re finding in the body? It’s cannabis. And it’s often a combination of cannabis and potentially alcohol and maybe even other things as well,” she told The Epoch Times.
Ms. Fischer explained that cannabis consumption affects a driver’s reaction time, particularly the ability to make “split-second decisions.”
She said the drug also affects “what you’re seeing; what you’re thinking; how you’re processing—vision, hearing, and so forth.”
The GHSA does not recommend against either alcohol or cannabis consumption but instead advocates responsible use and avoiding driving when under the influence.
“And so our message is very, very straightforward: just don’t consume and then get behind the wheel,” Ms. Fischer said.
Unfortunately, unlike alcohol which can be easily detected on a driver’s breath with a breathalyzer measuring exact levels of intoxication, it is difficult for police officers to screen drivers for cannabis impairment.
Ms. Fischer said that officers largely have two options in their arsenal for spotting cannabis intoxication in drivers.
Officers can be trained in Drug Recognition Enforcement (DRE), using a “systematic and standardized 12-step evaluation consisting of physical, mental and medical components,” according to the International Association of Chiefs of Police.
The other option, which is increasingly used throughout the country, is oral fluid testing.
A swab of saliva is taken from the driver’s mouth and tested for drugs.
“Depending on the drug used, dose, and route of administration, a drug may be detected in oral fluid in less than one hour and remain detectable for five up to 48 hours after last use,” according to LabCorp, one of the largest drug-testing companies in the country.
Oral fluid testing can also catch other drugs including amphetamine, MDMA, benzodiazepines, cocaine, opiates, and PCP.
However, oral fluid testing is problematic for substances like cannabis because of how long a single dose of THC is detectable in a user’s body.
According to the American Addiction Centers, THC is “detectable for up to 90 days in hair, anywhere between 1 day to a month or longer in urine [depending on how often the individual uses it], up to 24 hours in saliva, and up to 12 hours in blood.”
LabCorp says that some drugs can be found in oral fluid from “five to 48 hours.”
A driver could theoretically test positive for THC in an oral fluid test hours after residual effects elapse and long after any feelings of intoxication. If the driver is given a blood test instead, the results could be similar.
Ed Wood, legislative advocate for We Save Lives, a highway safety advocacy group, explained to The Epoch Times by email the issue of screening for cannabis intoxication with blood samples.
He asserted that “there is absolutely no correlation between the presence of THC in blood and the levels of impairment caused by THC.
“The presence of THC in blood implies impairment but does not prove it. Alcohol is the only drug with a proven correlation between blood concentration and level of impairment.”
“Drugged driving is indeed a serious problem. In Colorado’s 2020 data [the latest published], roughly half of all DUI/DWAI convictions can be attributed to drugs, with the remaining being attributed to alcohol only.
“The major cause of drugged driving is polydrug impairment, most of which is caused by a combination of alcohol plus THC.
“THC alone follows in importance, but we need to realize that of those THC-positive drivers arrested for DUI and convicted, over two-thirds are driving under the influence of both THC and other drugs,” he said.
Mr. Wood emphasized: “[Many] studies merely look at the presence of THC, not the presence of proven impairment.
“Only Colorado data do that, and that study shows the risk of crashing for those arrested for and convicted of impairment by THC only is about 10 times that of sober drivers.
“The risk of crashing for polydrug impaired drivers is even higher than that of drunk drivers,” he said.
Polydrug use occurs when someone consumes two or more intoxicating substances simultaneously.
Mr. Wood said that some of the studies on cannabis and impaired driving only feature cases where cannabis is smoked, not ingested in the form of edibles, which are becoming increasingly popular among regular cannabis users.
“The blood levels of THC in THC edible users rarely exceeds 5 ng/mL regardless of how much they have consumed. Yet they can be completely incapable of safe driving,” he said.
Ms. Fischer said often the best line of defense is police officers who are trained to look for the signs of impairment, regardless of what substances the driver may or may not have consumed.
“So we need those folks and we need them to continue to do this work.
“If you stop a driver and they’re clearly exhibiting some signs of impairment, but you can’t smell alcohol in the breath, they’re able to walk the straight line and [a] gaze nystagmus test doesn’t reveal anything, but there’s clearly something going on—there’s a good chance of some kind of drug, whether it’s legal or illegal, or a combination, there’s something going on here,” she said.
