The move to Schedule III marks the greatest change to U.S. drug laws since 1970 and represents a new future for the $32 billion cannabis industry.

President Donald Trump signed an executive order reclassifying marijuana from Schedule I to Schedule III, easing restrictions and enabling more medical research.

The president signed an executive order on Thursday to reschedule marijuana to a lower drug classification, one of the most significant changes to drug policy in decades.

"This risk is exacerbated by the fact that there is currently no proven, widely accepted standard to determine marijuana impairment at the roadside or before a driver begins operating a vehicle, making it far more difficult to prevent impaired driving," she added.

President Donald Trump is expected to reclassify marijuana from a Schedule I drug to a Schedule III drug on Thursday, CNN reports. Newsweek contacted the White House for comment via email after office hours.

Marijuana’s classification as one of the most dangerous and habit-forming substances has long drawn criticism.