Nearly Two-Thirds of Young People Admit to Cannabis Use and Driving

A study published in Psychology of Addictive Behaviors has raised serious concerns about the relationship between cannabis use and driving safety. Researchers at Western Kentucky University found a clear link: the more frequently a young person uses cannabis, the more likely they are to get behind the wheel while impaired.

The study followed 149 adults aged 18 to 29. All of them had reported driving under the influence of cannabis at least three times in the previous three months.

The Numbers Behind Cannabis Use and Driving

Participants averaged 25 instances of driving after cannabis use over three months. Nearly two thirds (61.7%) admitted to using cannabis while actively driving. That is not before a journey. That is during one. On average, they did so around ten times in that same period.

Participants also estimated spending roughly 31 hours per week in an intoxicated state. Nearly 39% drove after combining alcohol and cannabis. Research links this combination to additive impairment in lane control and divided attention tasks.

Cannabis use among young people in the United States is now at record levels. The 2024 National Survey on Drug Use and Health found that 38.1% of adults aged 18 to 29 used cannabis in the past year. Of those, 17.7 million used it daily or near-daily.

Frequent Use Increases Risk of Driving Under the Influence of Cannabis

The more days per month someone used cannabis, the more often they drove while impaired. Each additional day of use linked to roughly an 8% rise in how often they drove after consuming cannabis. A similar pattern held for riding with an impaired driver, using cannabis during a journey, and driving after combining it with alcohol.

Frequent users were also more likely to think they could consume larger amounts and still drive safely. Each extra day of cannabis use linked to a 2% rise in the amount someone considered safe before getting behind the wheel.

“More frequent cannabis users appear to underestimate impairment and engage in riskier driving behaviours,” the authors wrote.

Why the Tolerance Myth Makes Cannabis Use and Driving More Dangerous

Many frequent users believe that tolerance reduces their impairment. It does not. Laboratory studies show that even experienced users have measurable deficits in reaction time, vigilance, and complex driving tasks. They feel capable. The data says otherwise.

Cannabis impairs driving-related cognitive functions for two to five hours after use. The exact duration depends on the dose and method of consumption. Smoking or vaping cannabis while operating a vehicle makes this worse. It combines physical distraction with a steady build-up of THC throughout the journey.

The public still tends to view driving under the influence of cannabis as less dangerous than drink-driving. The evidence does not support that view. One estimate puts cannabis-related excess road deaths in the United States at around 6,800 per year.

Attitudes Did Not Match the Behaviour

Frequent users drove more dangerously. Yet their sense of danger, peer approval, and concern about legal consequences looked much the same as those of less frequent users. Heavy users appear to be driven by personal beliefs about tolerance rather than social pressure or fear of the law.

Standard campaigns built around legal deterrence or social norms may not reach these individuals. Interventions that focus on objective impairment evidence, such as actual reaction time data and hazard perception scores, are likely to carry more weight with this group.

Who Is at Highest Risk From Cannabis Use and Driving?

Daily and near-daily users carry the greatest risk. Among those who used cannabis on 20 or more days per month, 65.9% reported using it while driving. They did so an average of more than 14 times across three months.

Brief screening at campus health centres or GP surgeries could identify heavy users early. Healthcare professionals can then offer targeted education based on objective evidence rather than general warnings about risk.

A Road Safety Problem That Is Not Going Away

Cannabis is legal in a growing number of US states. Use among young people continues to climb. The road safety implications are hard to ignore. Frequency of cannabis use is now a well-established predictor of impaired driving, and the heaviest users carry the greatest risk.

Prevention campaigns, early intervention, and honest public education about what cannabis does to driving ability are all urgently needed. Feeling tolerant is not the same as being safe.

Source: thedrugreport