The Michigan Supreme Court ruled that Michigan’s Medical Marijuana Act (MMMA) protects registered patients who drive with marijuana in their system if they are not under the influence of marijuana.

The court’s decision was unanimous, and means that the MMMA’s protection supersedes the Michigan Vehicle Code’s prohibition.

The ruling reversed People v Rodney L Koon, a Court of Appeals decision that that erroneously held that the Michigan Vehicle Code “prohibits operating a motor vehicle with any amount of a schedule 1 controlled substance in the driver’s body, [even] if the driver used marijuana under MMMA.”

The court explained that having marijuana in the system does not mean that there is a visible or substantial impairment with regard to driving.   Michigan Supreme Court

Since the ruling by the Court of Appeals, numerous medical marijuana patients throughout Michigan to received convictions for driving with trace amounts of the marijuana in their blood.

For more information, see Michigan Supreme Court issues significant DUI / medical marihuana opinion.