Michigan: Supreme Court Rules That Medical Marijuana Act Exempts Patients From Zero Tolerance Per Se Driving Law

Michigan: Supreme Court Rules That Medical Marijuana Act Exempts Patients From Zero Tolerance Per Se Driving LawLansing, MI: The Michigan Supreme Court has determined that state-authorized medical cannabis patients possess legal protections from criminal prosecution in cases involving the internal possession of THC while driving.

In a unanimous opinion (People v Koon), the Court determined that patients who are compliant with the Michigan Medical Marihuana Act (MMMA) may not be criminally convicted of being ‘under the influence’ absent evidence of behavioral impairment. Michigan traffic safety laws classify the operation of a motor vehicle with any amount of THC in one’s system to be a criminal offense, regardless of whether or not they are impaired by the substance.

"The Michigan Vehicle Code’s zero-tolerance provision, MCL 257.625(8), which is inconsistent with the MMMA, does not apply to the medical use of marijuana," the Court ruled. "If defendant is shown to have been under the influence of marijuana, then the MMMA’s protections will not apply, and the prosecution may seek to convict defendant under any statute of which he was in violation, including MCL 257.625(8)."

The state’s zero tolerance per se drug law remains applicable to non-patients. Under these types of traffic safety laws, motorists are guilty per se (in fact) of a criminal traffic safety violation if they engage in the act of driving while detectable levels of certain controlled substances or, in some cases, their inert metabolites (byproducts) are present in the defendants’ blood or urine. Proof of actual impairment is not a requirement for a conviction under such laws.

Ten states – Arizona, Delaware, Georgia, Illinois, Indiana, Iowa, Michigan, Rhode Island, Utah, and Wisconsin – impose zero tolerance per se thresholds for the presence of cannabinoids and/or their metabolites. (State-authorized medical cannabis patients in Arizona and Rhode Island are exempt by statute from prosecution under these per se statutes unless the state can provide additional evidence of psychomotor impairment.) In May, Oklahoma lawmakers also approved zero tolerance per se legislation, House Bill 1441, criminalizing the presence of THC and its metabolites in a driver’s blood or urine. That law goes into effect on October 1, 2013.

Five additional states impose non-zero-tolerant per se thresholds for cannabinoids in blood: Montana (5ng/ml — law takes effect on October 1, 2013), Pennsylvania (1ng/ml), Ohio (2ng/ml), Nevada (2ng/ml) and Washington (5ng/ml).

Last month, Colorado lawmakers also approved legislation, effective as of July 1, 2013, stating that the presence of THC/blood levels above 5ng/ml "gives rise to permissible inference that the defendant was under the influence."

However, according to the United States National Highway Transportation and Safety Administration (NHTSA): "It is difficult to establish a relationship between a person’s THC blood or plasma concentration and performance impairing effects. … It is inadvisable to try and predict effects based on blood THC concentrations alone."

In addition, a 2013 academic review of per se drugged driving laws and their impact on road safety found "no evidence that per se drugged driving laws reduce traffic fatalities."

For more information, please contact Paul Armentano, NORML Deputy Director, at: paul@norml.org. NORML’s white paper, "Cannabis and Driving: A Scientific and Rational Review," is available online at: http://norml.org/library/item/cannabis-and-driving-a-scientific-and-rational-review.