Why science doesn't back up most drugged driving laws

This article looks at what's wrong with drugged driving laws and why they are often a threat to civil rights.

Drugged driving is a serious problem in Tennessee. As The Tennessean reports, drugged driving is now a more common factor in fatal traffic accidents in the state than drunk or distracted driving. That has led police to start cracking down on drugged drivers, especially for those who may be impaired by prescription drugs or marijuana. While trying to make Tennessee's roads and highways safer is certainly a laudable goal, drugged driving laws are often based on bad science and may do little to actually cut down on drugged driving. That's because such laws are often modeled around alcohol DUI laws, despite the fact that drugs and alcohol react differently from one another in the human body.

Bad science and drugged driving

When it comes to driving while impaired by marijuana, states generally model their laws on their alcohol DUI laws. Just as the law states that driving with a blood-alcohol content level above 0.08 is illegal, the law generally makes it illegal to drive with more than five nanograms of THC, the mind-altering compound in marijuana, per milliliter of blood. While that might sound like a sensible limit, there's not much science to show that people driving above that limit are actually impaired.

As The Washington Post reports, the reason using a THC limit to police drugged driving is so problematic is because THC reacts differently in different people. Somebody who consumes marijuana frequently, for example, will build up a tolerance which means that he or she may exceed the legal limit without being impaired. On the other hand, somebody who consumes marijuana infrequently could be highly impaired with even a low THC level.

Civil liberties jeopardized

The fact that so many drugged driving laws are based on bad science could pose a threat to individuals' civil liberties. One problem with measuring THC is that, unlike alcohol, THC can remain in somebody's system for days and even weeks after they consumed marijuana. That could mean that they could be convicted of driving while impaired despite not being under the influence of drugs.

That's why even traffic safety advocates, who usually push for tougher drugged driving laws, are starting to advocate for abolishing what are largely arbitrary limits on THC for drivers. The AAA Foundation, for example, says that instead of relying on legal limits, police officers should go through training to recognize the signs of drugged driving and be certified as drug recognition experts (DRE).

Charged with drugged driving?

Anybody who has been charged with impaired driving, whether it be for drugs or alcohol, needs to contact a criminal defense attorney immediately. An experienced attorney can help clients understand what legal options they may have, including how to mitigate the fallout that being charged with a DUI could lead to.