April 2

Michigan Declines to Establish Threshold THC Level to Prove Impaired Driving

Impaired-Driving-Report-650288-7

“On November 6, 2018, Michigan voters approved Proposal 1, creating the Michigan Regulation and Taxation of Marihuana Act (MRTMA). Among other things, this Act delegates responsibility for marijuana licensing, regulation and enforcement to the Michigan Department of Regulatory Affairs (LARA). LARA’s Bureau of Marijuana Regulation (BMR) is responsible for the oversight of medical and adult-use (recreational) marijuana in Michigan.”

Six states have set impaired driving thresholds of Delta 9 THC in blood, ranging from 1 to 5 ng/ml. Those states are Colorado, Montana, Nevada, Ohio, Pennsylvania, and Washington.

Michigan’s Impaired Driving Safety Commission, after study, declined to recommend that Michigan adopt any impairment threshold for Delta 9 THC because the commission determined that blood plasma concentrations of Delta 9 THC are not a reliable indicator of whether an individual is impaired.

“Therefore, because there is a poor correlation between Δ9-THC bodily content and driving impairment, the Commission recommends against the establishment of a threshold of Δ9-THC bodily content for determining driving impairment and instead recommends the use of a roadside sobriety test(s) to determine whether a driver is impaired.”