Reefer Madness: 'Driving While High' Laws Aren't Based on Science, Says Study

Steph Willems
by Steph Willems
reefer madness 8216 driving while high laws arent based on science says study

Impairment tests used by authorities in U.S. states where marijuana use is legal in some form have no basis in science, and their results essentially mean nothing, a recent study concludes.

Commissioned by the American Automobile Association’s safety foundation, the study found that no blood test for THC, the active ingredient in marijuana, can accurately determine a driver’s level of impairment, the Associated Press reports.

The finding blows law enforcement’s main method of convicting high drivers into the weeds.

In five of the six states that recently legalized marijuana, a motorist is deemed guilty of impaired driving if their blood level of THC passes a certain threshold.

Because impairment levels are highly variable and depend on the individual, rather than blood THC levels, the tests lead to some motorists being wrongfully charged, with others going free, despite being high as a kite at the time of the test.

Regular users, be it stoners or medicinal users, often show lower levels of impairment than intermittent users. Their blood, however, often contains THC for longer periods than a once-in-a-while weed smoker. TCH tests that minic the blood alcohol tests administered to drunk drivers won’t recognize these distinctions.

AAA wants the tests scrapped and replaced with an observation-based system, where trained officers analyze a number of physiological and behavioral indicators to determine a person’s level of impairment.

“There is understandably a strong desire by both lawmakers and the public to create legal limits for marijuana impairment in the same manner we do alcohol,” said Marshall Doney, AAA’s president and CEO. “In the case of marijuana, this approach is flawed and not supported by scientific research.”

The six states that use the blood test — Ohio, Nevada, Washington, Colorado, Montana and Pennsylvania — could be joined by more states this fall. Their ranks could double, in fact, as lawmakers seek a way of detecting high drivers.

The study is a buzzkill for law enforcement members and state-level bureaucrats, but if the sole purpose of the THC blood test is to make roads safer from impaired drivers, its findings beg for acknowledgment.

North of the border, Cannabis — erm, Canada — plans to legalize marijuana use in the near future. The study will be of interest to their authorities, too.

A New York University professor quoted by the Associated Press said there’s a number of marijuana-related laws in need of fixing. Mark A. R. Kleiman, who specializes in drug and criminal policy, said several states have laws against motorists having any THC in their bloodstream, despite the fact that trace amounts can linger weeks after the individual became sober as a judge.

A noisy child in the backseat of a vehicle is as big a risk factor as using marijuana, Kleiman said.

[Image: Check Grimmett/ Flickr ( CC BY-SA 2.0)]

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  • Ttacgreg Ttacgreg on May 11, 2016

    A large number of comments here are basing their opinions on the assumption that being stoned impairs driving. Reassess that basic assumption. It at necessarily so. I have said this on this website before as well as other ones. Until the mid 80s I (gave it up) used to, and I still do currently know plenty of people who duck into the trees while skiing, they get good and baked, and go right out and the ski bumps with no problems. Driving a car is literally child's play in comparison. The sensory motor coordination and judgmental complexity of skiing bumps is far far more demanding. It only takes a lapse of less than a second's time in any one of the aforementioned two skills to result in loss of control and a likely fall. Hell, I bet I logged nearly 100,000 miles driving while smoking cannabis back in the day. It was especially helpful in the boring to tears 55mph era to pass the time and make driving the Interstates at that stupidly low speed more entertaining.

  • ToddAtlasF1 ToddAtlasF1 on May 12, 2016

    Here's a thought: Let's look at actual accidents and prosecute the people who caused those accidents. Crashed cars are crashed if the person who ran the red light was putting on make up or sniffing glue. People crushed while drinking coffee at a sidewalk cafe are dead whether the driver that left the road was senile or just tried tequila for the first time. I've seen people walk away from causing horrible damage because they were found not to be drunk. Most accidents are caused by people who aren't drunk. Why does being sober take away responsibility for one's actions? Drinking and driving is making a bad decision. So is almost anything else that results in accidental harm to another. DUI is an industry. Limits are now lower than make any sense for the majority of the population. Punishments are higher in some places for driving while not actually impaired than they are for causing a death with your car while merely incompetent. It is absurd.

    • See 3 previous
    • Rpn453 Rpn453 on May 12, 2016

      The general population prefers having their lives dictated by issues of morality. This is more pleasant to them than the idea of being held responsible for the consequences of their decisions. That way, when they harm someone through negligent behavior, it was just a mistake that the higher powers will forgive, since they were behaving morally.