Drugged Driving THC Fact Page - OUID Lawyer

Grand Rapids Operating Influence of Marijuana Defense Lawyer

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Marijuana, THC and Drugged Driving in Michigan.


As more states enact medical and recreational marijuana laws, the new marijuana laws directly conflict with long-enshrined, strict Zero Tolerance prohibitions on driving under the influence of any Schedule 1 drug, which includes cannabis, more commonly known as marijuana.

It is important to note that ALL STATES prohibit driving a motor vehicle if your ability to operate a vehicle safely is compromised or impaired. If you are impaired by any substance, you are not allowed to drive, whether you are impaired by prescription drugs, alcohol, cocaine, marijuana, water, vitamins, etc. The important difference between drunk driving and drugged driving, is that with alcohol there is a federally mandated .08 blood alcohol content (BAC) limit. Contrary to public perception, it is not illegal to drink and drive so long as your ability to operate the car safely is not impaired AND you are not over the presumed drunk driving legal limit of .08.

In cases involving low alcohol readings under .08 or someone who is impaired by prescription drugs, the prosecuting attorney must prove impairment of the driver beyond a reasonable doubt. Impairment can be shown by evidence the driver was weaving, driving over the fog line, erratic driving, failure to use headlights, speeding, and failure on the roadside sobriety tests. A jury would deliberate and have to decide whether the state or local prosecutor had proved impairment beyond a reasonable doubt.

Recreational Marijuana and Driving with Active THC
The Michigan Regulation and Taxation of Marijuana Act provides relief. The recreational marijuana law allows a driver (age 21 or older) to operate a car so long as they do not do so "under the influence" of marijuana.

No Reliable Test or Studies as to THC Impairment Levels.

Unlike alcohol, there are not enough indicators that lead to setting a specific per se intoxication/impairment limit for active THC. The effects of alcohol are rather predictable and the studies on alcohol and driving are innumerable. Marijuana and its effects on drivers is much more subjective and individualized. The studies that do exist tend to show that users of marijuana act the opposite of drunk drivers. Drivers with marijuana in their bodies tend to slow their driving, allow more distance between cars, and drive more carefully. Unlike alcohol, which is a stimulant and has been shown to limit a drinkers inhibitions and make them feel they are superman (or superwoman) and thus impervious to harm, marijuana tends to act more like a sedative and its users become more cautious and careful.

However, the majority of other states still have zero tolerance laws on the books, and in these states, driving a motor vehicle with any amount of active-THC in the bloodstream can lead to a drugged driving conviction, just as if you were driving over the alcohol legal limit of .08.

Arbitrary THC Levels.

There seems to be a lot of legislative will to set arbitrary active THC standards. This may be in part, because marijuana is highly controversial and because there are few scientific studies that are considered unbiased. To date there are simply no studies that demonstrate with any reasonable certainty a certain amount of THC causes impairment. The legislators that passed laws setting a .05 ng/ml limit would no doubt readily admit that this amount is not based on any scientific study or data.

How Long after I Smoke Marijuana Will Active THC be in my Body?

There is no easy answer. There is some scientific support that shows that smoking cannabis acutely affects driving abilities for the first hour. Active THC levels begin drop over the next two hours, followed by a residual period which lasts 2-3 or more hours. If marijuana is orally ingested, THC levels peak 2-3 hours later.

Assuming that the cannabis ingested is not a high THC strain, THC levels should drop below 5 ng/ml about 4 hours.

Active THC vs 11-Carboxy-THC.

The Michigan Supreme Court (People v Feezel, 2010) ruled that the marijuana metabolite "11-carboxy-THC" (the substance that stays in your body for up to 28 days) was a 'derivative' of marijuana As a derivative, 11-carboxy-THC is not a Schedule 1 controlled substance. Thus, a person who only has the metabolite cannot be prosecuted for zero tolerance drugged driving. Thus it not illegal to drive with 11-carboxy-THC metabolite in your body in Michigan. But be aware that driving with the marijuana metabolite is still illegal in many states.