
Despite several states decriminalizing Marijuana use it is very important for fleets to know that it is still illegal for truck drivers under federal rules. To learn more read the article following article from Transportation Topics magazine
Last month, scientists at Quest Diagnostics delivered a stark message to U.S. employers: marijuana use among workers is rising—and it’s showing up in drug-test results.
“Our analysis confirms that marijuana use is not only present in today’s workforce, but continues to increase,” said Barry Sample, Quest’s director of science and technology. As marijuana laws evolve, he added, employers must carefully assess the risks drug use poses to employees, customers, and the public.
Quest’s review of 10 million drug tests conducted in 2018 found higher marijuana positivity rates across every segment of the workforce. Sample also noted an uptick in efforts to tamper with or evade testing. The data include federally regulated, safety-sensitive transportation workers—most notably commercial truck drivers.
While Quest does not break down results by specific job titles, Sample said commercial driver’s license holders subject to testing by the Federal Motor Carrier Safety Administration make up the largest share of the safety-sensitive workforce.
Quest reported that marijuana positivity rates among federally mandated, safety-sensitive urine tests increased nearly 5% from 2017 to 2018, and almost 24% since 2014. Although this group has not seen increases as sharp as other workforce categories, Sample called the trend troubling.
Officials at the U.S. Department of Transportation say education remains a key focus. Patrice Kelly, director of DOT’s Office of Drug, Alcohol, and Compliance, said the agency continues to emphasize that marijuana use is prohibited for truck drivers—regardless of state laws or medical authorization.
“We are very clear that medical review officers will not downgrade a positive marijuana test, even if the individual claims medical use,” Kelly said at a recent federal drug-testing advisory meeting. She acknowledged, however, that marijuana policy remains complex due to the lack of a national standard for measuring impairment.
Sample said his biggest concern isn’t just rising positivity rates—but a sharp increase in post-accident drug test failures compared with pre-employment testing.
“Historically, those rates were similar,” he said. “In 2012, post-accident tests were only about 2% higher. By 2018, they were 30% to 40% higher.”
Abigail Potter, manager of safety and occupational health policy at the American Trucking Associations, said inconsistent state marijuana laws are adding confusion for drivers and employers alike.
“Legalization across a patchwork of states has not made compliance easier,” Potter said. “Drivers are confused, and so is the general public.”
Still, she noted that drug-test positivity rates among truck drivers remain lower than those of the general workforce. Even so, DOT policy is unequivocal: marijuana use is prohibited for truck drivers, whether recreational or medical. For other transportation employees, rules may vary by state and employer—but marijuana remains a federally illegal Schedule I substance.
Potter advised employers to consult legal counsel when setting marijuana testing policies for non-driver roles to ensure compliance with state law.
Legal complexity is growing, according to Faye Caldwell, a partner at Caldwell Everson. She said 33 states and Washington, D.C., have decriminalized marijuana in some form, though only 11 states and D.C. allow recreational use. Most states prohibit driving while impaired, but few define what marijuana impairment actually means.
Compounding the issue is marijuana’s increasing potency, said Charles LoDico, senior chemist and toxicologist with the Substance Abuse and Mental Health Services Administration.
“This isn’t the marijuana people remember from decades ago,” LoDico said. While average THC levels hovered around 4% in the 1980s, today’s products commonly range from 13% to 20% or higher.
“There’s a perception that marijuana is harmless,” he said. “But there are well-documented risks.” Acute effects can include impaired memory, reduced ability to perform complex tasks, increased risk-taking, and panic attacks.
With more than 90% of the U.S. population now having access to marijuana for medical or recreational use, LoDico said the implications for workplace and roadway safety should concern everyone.