Is it Safe to Drive if You’re Stoned? An Investigation

We look into whether hitting the accelerator after hitting the blunt is in any way better than drunk driving.
Shamani Joshi
Mumbai, IN
Is it Safe to Drive if You’re Stoned
Photo courtesy of why kei (left) and Chase Fade (right) / Unsplash

It was an ordinary (by pre-COVID standards) Saturday night for Abhijit Kelkar*, a 27-year-old Mumbai-based video producer, as he simmered in a hotboxed room blasting pop music, surrounded by a handful of his closest friends. Even as cacophonous chants of his friends begged him to do a round of kamikaze shots, Kelkar refused. Instead, he chose to carefully crush a cannabis bud between his fingers and rolled his third joint for the night. Kelkar, who had just bought a new car, knew he couldn’t risk getting pulled over for drinking and driving. Instead, he chose what he considered a “healthier and safer” alternative.


Smoking weed and driving has been the stoner’s solution to getting high without having to leave the car behind ever since the Seth Rogen brand of movies made it cool. “I definitely prefer smoking up and driving because I feel way more in control,” says Kelkar. Though he insists that any act that compromises a person’s spatial awareness and alertness while driving is morally wrong, Kelkar also believes he’s reached enough of a comfort level with the cannabis high to trust his stoned instincts. He’s not the only one.

In a 2019 study by PSB Research and Buzzfeed News, half of Americans surveyed said they believed it was safe to smoke weed and drive. While a review of 60 studies presented in 1995 at the International Conference on Alcohol, Drugs and Traffic Safety concluded that marijuana affects all cognitive abilities key to driving safely, including tracking, motor coordination, visual function and focus, users point out how being baked can make them risk-averse and more careful about estimating distance.

Around the world, there is no standardised way to measure how impaired a stoned driver is (unlike the clear-cut way to define how drunk a driver is), and field sobriety tests are usually only relevant to alcohol.

There are marijuana breathalysers out there but there is no clear correlation between how much THC (the psychoactive component of cannabis) can be objectively linked to impaired driving.


Then, there’s also the issue that THC, which is detectable via blood in a person’s system for a month, and stored in a person’s fat cells, lingers in the user’s body long after their high has worn off.

Also, while THC levels might spike as soon as a person has smoked a joint, their driving skills might not yet be impaired since it might not have reached their brain.

Though countries like Canada have legal limits when it comes to the amount of THC that can be in a driver’s system, an anecdotal VICE investigation found that it was nonetheless confusing to both, the drivers and the authorities.

And it’s the same for patients in states which have legalised medical marijuana. Despite the law stating that no one, not even a patient, is allowed to drive after consuming cannabis, the ambiguity of what is considered “low levels” provides a proverbial pothole for users.

In Australia, roadside drug tests have often come back with false results, making people question their veracity. Meanwhile, in most countries in Asia, where weed is often socially acceptable but continues to be illegal and criminalised, these tests are impossible to administer. Add to that the fact that roads in countries like India have far more traffic and obstacles, and you realise that there is no global evidence to link safety and smoking up.

“Once, I was driving in heavy traffic stoned, and the time dilation made it feel like hours, so I decided to shut my eyes and listen to soft music even while my car, which was on automatic mode, was going forward” Aditya Kumar*, 23, an IT engineer from Bengaluru told VICE. “The next thing I know, I’d nodded off and crashed into the car in front of me.” While Kumar got away with just a few light bruises and a crushed car bumper, that was the last time he decided to drive stoned. “I learnt my lesson but also am grateful that I didn’t get caught by the cops. If I had alcohol on my breath, this would’ve panned out very differently.”


Though no one was injured here, cases like Kumar’s do exemplify the risks involved. But real-life cases and science still do not have one clear-cut answer to the question. In fact, a 2017 study by the U.S. National Highway Traffic Safety Administration found that stoned drivers were actually more careful, exhibiting “reduced mean speeds, increased time driving below the speed limit and increased following distance during a car following task.” Which means, chances are that you won’t be putting yourself in danger of rash driving or overspeeding when blazed, but might be pulled up for or frustratingly honked at by other drivers for just really slow driving.

But, a study published in the journal of Drug and Alcohol Dependence in January 2020 found that surveyed users, especially those who regularly smoked marijuana before the age of 16, displayed impaired driving abilities long after their high had come down. This study did mention that the same effects were not recorded in medical marijuana users, and even said it wasn’t a decisive conclusion.

Still, there is enough medical evidence to suggest that weed, just like alcohol, does affect your actions.

“Driving uses two parts of your brain: your conscious actions and cognitive actions,” Dr Prashant Punia, a neurosurgeon based out of Pune, India, told VICE, explaining that instinctual actions from the conscious part of a person’s brain are affected more by alcohol than marijuana. “Marijuana can have a peculiar effect on your brain’s cerebellum, which is responsible for motor functioning. Depending on the dosage, this makes it tough to multitask cognitive actions like following the GPS, avoiding potholes or staying in your lane.” Punia points out that the effects of marijuana are far more subjective than alcohol, and would differ from person to person, requiring more intensive research to make a measurable variable. “While some studies suggest that you overcompensate and are more cautious while driving high, there isn’t enough objective research to support these claims.”


Much research states that ideally, users should at least wait till their high dies down before getting behind the wheel. A study undertaken by Canada’s McGill University states that a person should wait at least five hours after they’ve smoked cannabis before they drive. Other research suggests anywhere from four to six hours. Except, the high may not always be determined by the time.

“I don’t think I’ve ever felt ‘too high to drive’, but in case I take a bong hit or get totally blazed, I prefer to wait out the high before getting behind the wheel,” says Rajesh Kapoor*, a 22-year-old entrepreneur from Delhi. Kapoor also points towards a mild experience of anxiety that sometimes accompanies him while he’s driving high, compelling him to be more careful.

“I don’t have a cut-off to the number of joints as such, because my tolerance has increased over time, and it takes almost three joints to feel the effects that one joint used to have,” says Kelkar. “However I follow my instinct. If I feel like there’s any reason at all to doubt whether I’ll be able to drive, I just won’t get behind the wheel.”

Follow Shamani Joshi on Instagram.

*Names changed to protect identities

VICE India in no way endorses the illegal usage of marijuana or other narcotics. The content above is intended for entertainment and informational purposes only, and is not meant to propagate the use of any illegal substance. See Terms of Use for more.