Driving While High: Not a Risk Worth Taking

Blurry Night Traffic Lights
Photo by: Virote Chuenwiset/Shutterstock

As a society, we are so past the point where impaired driving is cool. Too many people have lost their lives due to the irresponsible choices of inebriated drivers getting behind the wheel of a car. Mothers Against Drunk Driving was founded in 1980, a year when nearly 25,000 people died as a result of intoxicated use of a vehicle. Since then, awareness has skyrocketed and death toll numbers have declined, though there is still some confusion in an area that is anywhere but grey.

The guy who brags about slamming beers before driving home? He’s a reckless douche bag. The person who giggles about driving after an intense hot box sesh? They are no better.

Driving under the influence is never okay.

And, as you probably guessed, being high is being under the influence. Drugged driving is dangerous, deadly, irresponsible, and illegal.

Cannabis and Driving

Drunk drivers are involved in nearly 25 percent of motor vehicle fatalities; a portion of that percentage includes drivers that test positive for cannabis use. Research tells us that both weed and booze impair driving-related skills, but the effects of cannabis show more variation, due to tolerance levels, smoking techniques, and different forms of absorptions. It’s clear, however, that any amount of high leads to weakened driving.

Cannabis has very clear effects on the body that relate to driving. Marijuana use has been shown to impair several key driving skills, which include reaction time, target detection, and tracking ability.

Cognitive skills take a major hit: attentiveness, vigilance, perception of time and speed, and use of acquired knowledge are all affected by cannabis, according to research listed by the National Center for Biotechnology Information. This is in addition to tracking, motor coordination, and visual functions. Judgement and anticipation are also altered, as well as executive functions like route-planning and risk-taking.

It’s important to note that while people under the influence of alcohol usually underestimate their level of impairment, those under the influence of cannabis tend to over-shoot it. Both are equally problematic. Drivers who used marijuana typically driver more slowly, take less risks, and follow the other cars on the road at farther distances. And while this might seem like a great alternative to boozy drivers who speed, tailgate, and make risky moves, this level of cautionary driving can cause accidents too, in conjunction with cognitive impairment.

Some people think that it’s okay to drive when feeling only “a little high,” akin to having only one or two beers, before tipsiness sets in.

The problem with being “a little high” while driving is that impairment isn’t one-size-fits-all, and it’s hard to know what “buzzed” looks like in the world of cannabis; marijuana impairment is hazy. There isn’t a tracking system based on sex, weight, and how much you’ve consumed. According to lifehacker.com, alcohol has a set system of absorption, distribution, and elimination from the body that varies very little, while the processes are much more complex for marijuana. The amount of THC you have in your system isn’t necessarily a direct measure of impairment.

We also know how difficult it is to test exactly how much THC someone has consumed because THC stays in your system for much longer than just after your high.

Consequences of Driving High

a car accident between 2 cars

The consequences of driving high are countless. Two main reasons, however, are danger and illegality.

Just because a substance is legal does not mean that driving while using that substance is. For example, alcohol is legal, but drunk driving is not. Prescription drugs like oxycodone and codeine are legal with a prescription, but operating machinery while using them is not. Similarly, even in places where marijuana is legal for recreational or medicinal use, it’s illegal to drive while high.

With alcohol, there’s a standard system in place to catch drunk driving. A breathalyzer test reveals a blood alcohol concentration, which, when over the .08 limit, means a guilty charge. There is no breathalyzer equivalent in the cannabis world (yet), though law enforcement has methods of determining sobriety. These can include field sobriety tests or a drug-influence evaluation which considers factors like blood pressure, pupil size, and eye color.

Some states have per se DUID laws: if a blood test shows more than (generally) 5 nanograms of THC per milliliter of blood, there is a violation of the Driving while Under the Influence (DUID) law. A few states have zero-tolerance laws, where anyone found with any measurable level of THC in their blood is violating the DUID law.

Most states, however, have effect-based DUID laws, where a prosecutor must convict a driver through proof of impairment or incapacity at the time of an accident or traffic stop. Though the DUID laws are different per state, there is no state in the U.S. where it is legal to drive impaired, under the influence of cannabis and alcohol alike. Doing so is never advisable.

The stats are clear: car accidents are the fifth leading cause of death in the U.S.; 38,588 people were killed in 2006, and motor vehicle accidents are the nation’s leading cause of death in those under 30. The National Institute on Drug Abuse states that two large European studies discovered that drivers who tested positive for THC in their bloodstream where roughly twice as likely to be culpable for a fatal crash than those who were sober. They also claim that the risk of being in a crash doubled or more than doubled after marijuana use.

Wait It Out

bud growing on black background

When in doubt, research suggests that users wait a minimum of three or four hours (minimum is the key word here) before driving after consuming cannabis. Do not get behind the wheel if you feel at all “a little high” or even if you just feel barely buzzed.

The bottom line is simple: don’t drive while impaired. Cannabis and driving don’t mix; wait out the high before getting behind the wheel of a car.