Truth or Myth: “I Drive Better When I'm High”

It’s a myth that drivers can safely operate a car after smoking or ingesting cannabis (also known as marijuana, weed, or pot).

Since the legalization of recreational cannabis, impaired driving rates have increased. A recent survey showed that drivers’ use of cannabis had spiked by forty-six percent since 2007 (AAA n.d.).

Some cannabis consumers may think driving high “isn’t as bad as driving drunk,” but cannabis can be just as risky.

How Does Cannabis Affect Driving Ability?

Cannabis affects the body in many ways, and often unpredictably—different people may have varying experiences with cannabis, which makes it difficult to pin down exact outcomes.

One guideline that applies to every driver: there’s no safe amount of cannabis a person can take before driving.

Unlike alcohol’s Breathalyzer, there is no test to determine the level of cannabis impairment. A consumer may also be unaware of how potent their cannabis is, which could lead to an unexpectedly intense high. Read more on cannabis potency here.

Below are a few ways that cannabis affects driving:

• Cannabis impairs attention. Staying alert is vital in the fast-paced environment of the roadways. Distracted drivers are more likely to make mistakes.
• Reaction time is slower when high—and anyone who’s been in an accident knows it only takes seconds for something devastating to happen.
• The substance impairs coordination and visual perception, which may also contribute to misjudgments in space and time. This could translate to swerving or following another vehicle too closely or too distantly.
• Cannabis affects areas of the brain that control movement, potentially slowing the physical capabilities of a person who’s consumed the drug.
• When mixed with other substances, the effects of cannabis can be magnified. Alcohol and cannabis are a common combination; both substances can lead to drowsiness and difficulty with judgment.
• For young drivers who aren’t as experienced, cannabis adds to the risk for vehicle crashes.

What Drivers Can Do

• Don’t get behind the wheel if you’ve consumed cannabis. There is no risk-free, safe amount a person can take. Even small doses of cannabis can cause side effects.
• If there is a chance you may consume cannabis or any other substance, make a plan to get a ride or take a rideshare.
• Be aware of cannabis’s release time—products with edible forms of cannabis can take between thirty minutes and several hours to take effect. Although a person may feel sober right after consuming edibles, it’s hard to predict when the effects will kick in.
• Similarly, a cannabis high can last anywhere from two to ten hours, depending on many factors (Santos-Longhurst 2020). It’s best to stay put if you’ve consumed something. Don’t assume it’s “been long enough.”
• Remember: even if cannabis is legal, impaired driving isn’t. Driving under the influence of any substance is punishable by law.
• Be aware of other drivers! Even if you are sober, use caution during nights and weekends, which are common times that others may be using substances.

For more information on cannabis, driving safety, or managing substance use, contact LEAF at (607) 432-0090.

Sources:

AAA. “Cannabis & Driving.” n.d. Accessed May 15, 2024. https://exchange.aaa.com/safety/substance-impaired-driving/cannabis-driving/.

Centers for Disease Control (CDC). “Cannabis and Brain Health.” February 15, 2024. https://www.cdc.gov/cannabis/health-effects/brain-health.html?CDC_AAref_Val=https://www.cdc.gov/marijuana/health-effects/brain-health.html.

HealthyChildren.org. “Driving While High: Why Marijuana and Driving are a Dangerous Mix.” October 11, 2023. https://www.healthychildren.org/English/ages-stages/teen/substance-abuse/Pages/Driving-While-High-a-Dangerous-Mix.aspx.

Santos-Longhurst, Adrienne. “How Long Does a Cannabis High Last?” Healthline. February 28, 2020. https://www.healthline.com/health/how-long-does-a-marijuana-high-last#onset.