Limited research on the effect of legalizing marijuana throughout the U.S. on truck driver safety is too limited to make a hard connection between the two, according to a new study.
Impacts of Marijuana Legalization on the Trucking Industry, released on Monday by the American Transportation Research Institute (ATRI), points out that research available so far has found that driving under the influence of marijuana causes impairment, which does negatively affect highway safety.
In addition, initial data suggests that legalizing marijuana has negatively impacted highway safety, particularly in the case of increases in nonfatal crashes.
However, “it is too soon to calculate the relationship between legal marijuana and highway safety outcomes,” ATRI emphasized.
“The impacts of impairment on individual drivers and overall highway safety have yet to be adequately documented through research. Testing impaired individuals through a quantitative measurement — which has been key to combating drunk driving — remains elusive in the case of marijuana. More research is needed.”
ATRI, a nonprofit overseen by large trucking companies and the American Trucking Associations, uses much of the report to outline marijuana legalization trends, past research on marijuana use and driver impairment, and the current state of federal enforcement measures aimed at detecting marijuana abusers in trucking.
The group also received responses from more than 200 carriers – most of which employed 25 or fewer drivers – on an array of marijuana-use related questions in a survey conducted in early 2023.
“Given their extensive driving experiences, truck drivers were asked if they thought highway safety, in general, had been negatively impacted by legalized recreational marijuana,” the report stated. “The majority (55.4%) indicated that they believed highway safety had not been impacted.”
ATRI also sought updated sentiment on carriers’ truck driver hiring practices as they related to marijuana use. The majority (56.3%) responded they were willing to hire a driver with a prior positive drug test. However, ATRI noted, 43.7% responded that they would not, “thus exacerbating the number one industry issue among trucking company executives, the driver shortage.”
Most respondents (62%) were in favor of changing federal drug testing policy. Of those, nearly half (47%) believed that a sobriety or impairment test was needed (as opposed to a more general drug-use test) to help distinguish between drivers that used marijuana during their personal time versus drivers who use marijuana while on duty.
Other respondents (27.6%) felt marijuana should not be treated as a Schedule I drug, which would lift current restrictions on drivers against using it recreationally or under medical supervision.
Another group (14.9%) responded that stricter drug laws are needed or additional testing options such as hair testing should be recognized, according to the survey.
ATRI noted that if the federal government chooses to keep marijuana a prohibited Schedule 1 drug, carriers will continue to place thousands of drivers in prohibited status every year, with the trucking industry losing them to jobs that do not do marijuana testing. “Ultimately this puts pressure on the availability of CDL drivers,” ATRI stated.
“It is possible, however, that federal marijuana rules will evolve toward legalization and ultimately marijuana will be removed from the federal Schedule I designation. Any shift toward federal legalization would likely ease pressure on the industry’s driver shortage.”
But to ensure that the trucking industry remains safe if such a change were to occur, ATRI supports the development of a national impairment test standard along with protections for carriers that choose to screen for marijuana.
“Carriers ultimately are responsible for the safe behavior of their drivers and must maintain a zero-tolerance position for on-the-job marijuana impairment, regardless of federal marijuana designations,” the group stated.