Survey: Most Truck Drivers and Their Carriers Favor Changes in Federal Marijuana Testing Rules

Roughly two-thirds of US truck drivers and their carriers favor changes in federal marijuana testing regulations, according to survey data compiled by the American Transportation Research Institute.

Seventy percent of truck drivers and 62 percent of representatives from motor carrier companies said that “changes were needed to federal drug policy rules in light of state-level legalization.” Sixty-five percent of all respondents agreed that some form of marijuana impairment testing should “replace marijuana use testing.”

Currently, 41 percent of all US truck drivers reside in a jurisdiction where the adult use of marijuana is legal.

Federal law mandates that commercially licensed drivers be subject to both pre-employment and random marijuana urinalysis testing, which detects the presence of the inert carboxy-THC metabolite. This non-psychoactive metabolite can be detectable in subjects’ urine for weeks or even months following past exposure, long after any potential effects have worn off. According to data published this summer in the Canadian Journal of Public Health, employees who consume cannabis during their off-hours possess no greater risk of occupational injury than do those who abstain from marijuana altogether.

Since 2020, over 100,000 truck drivers have tested positive for past exposure to marijuana. The majority of those positive tests came via pre-employment screening. Those who fail random tests are required to enter a ‘return to work’ program, which includes passing a drug test, in order to have their license reinstated. However, only about one-quarter of those with drug test failures have done so — resulting in driver shortages and supply chain issues.

The survey’s authors acknowledged that existing federal testing regulations are contributing to significant numbers of truck drivers leaving the industry while also dissuading new workers from entering it.

They concluded: “The federal prohibition of marijuana use by CDL holders has been highlighted as a potential disincentive for drivers to stay in the industry. … Marijuana [also] contributes to a higher percentage of positive drug tests in the pre-employment category than in the overall testing data – on average 71.1 percent of positive drug tests are positive for marijuana. Therefore, past use of marijuana – which may have been up to 30 days prior to the test – is filtering out a significant number of potential truck drivers from the industry.”

In 2022, Congressman Earl Blumenauer (D-OR) sent a letter to the Transportation Department calling on the agency to amend policies that penalize commercially licensed drivers who consume cannabis while away from the job. It stated: “[Y]our department’s zero-tolerance policy sweeps up drivers who were unimpaired, drivers who have not used cannabis for weeks or even months. … Penalizing safe drivers who comply with state cannabis laws harms both the drivers and the supply chains they support.”

Last March, the US Department of Transportation finalized a new rule authorizing commercially licensed drivers the option to undergo oral fluid testing as an alternative to urinalysis. Saliva testing typically identifies residual traces of THC for up to 24 hours following marijuana exposure, a period of time beyond the window of cannabis-related impairment, but one that is far shorter than the timeline associated with urine testing or blood testing. 

NORML has repeatedly argued that employers should not presume that the detection of either THC or its metabolites is evidence of impairment. Alternatively, NORML has called for the expanded use of performance-based tests, like DRUID or Predictive Safety’s AlertMeter.

Writing in a new syndicated op-ed, NORML’s Deputy Director Paul Armentano said: “Requiring would-be hires and employees to undergo urine screens for past cannabis exposure are invasive and ineffective. They neither identify workers who may be under the influence nor contribute to a safe work environment. … Those who consume alcohol legally and responsibly while away from their jobs aren’t punished by their employers unless their work performance is adversely impacted. Those who legally consume cannabis should be held to a similar standard.”

Earlier this month, Michigan regulators halted pre-employment marijuana screens for most public employees in non-safety sensitive positions. Lawmakers in Nevada and Washington have also adopted similar bans.

Additionally, the District of Columbia, California, Connecticut, Minnesota, Montana, New Jersey, New York, and Rhode Island have amended their laws so that many employees are no longer terminated from their jobs solely because of a positive drug test for THC metabolites. 

Additional information is available from the NORML Fact Sheet, ‘Marijuana Legalization and Impact on the Workplace.’