The American Trucking Associations (ATA) is calling attention to the negative consequences for highway safety and safety-sensitive industries that could result from the U.S. Drug Enforcement Administration’s proposal to reschedule marijuana from a Schedule I to a Schedule III drug.

In anticipation of the proposed rule, ATA sent a letter to express these concerns to Attorney General Merrick Garland, Health and Human Services Secretary Xavier Becerra and Transportation Secretary Pete Buttigieg.

The reclassification could prohibit certain industries from screening for marijuana use by workers performing safety-sensitive roles, the ATA letter stated.

“If the trucking and broader transportation industries’ ability to conduct drug testing for marijuana use is restricted, the risk of impaired drivers operating on our nation’s roadways undetected would increase,” the associations stated.

“ATA believes that it is vitally important that your agencies ensure an ongoing allowance for marijuana testing of safety-sensitive workers to avoid deterioration of highway safety,” wrote American Trucking Associations Senior Vice President of Regulatory Affairs and Safety Policy Dan Horvath. “If this rulemaking is permitted to move forward without appropriate regulatory review, oversight and deliberation, ATA is concerned that it will severely curtail the ability of motor carriers and other employers of safety-sensitive positions to maintain a safe working environment, threatening the safety of all road users.

Marijuana and alcohol remain the most detected drugs in impaired driving incidents and state-level marijuana legalization has been linked to an uptick in crashes, the ATA added.

Just this week, Quest Diagnostics released alarming research indicating drug test cheating is on the rise.

Without additional action,the ATA said, deregulation or rescheduling of marijuana could preclude testing for all professional drivers and transportation workers as part of the DOT testing program.