Driving High

Injuries are the number one cause of death for people between 15 and 24 years of age in Canada. We know that young people are excited by taking risks and thrill seeking. This is because the part of the brain that controls emotions develops faster than the part of the brain that controls rational thought (including planning and impulse control). It’s not surprising that youth often make decisions that leave adults shaking their heads. Add marijuana use to the mix, and a youth’s ability to make good decisions decreases dramatically. Combine these factors behind the wheel of a car, and you create the perfect storm for a collision, often with deadly consequences.

FACT: Marijuana impairs your ability to drive.

  • According to studies published by the Canadian Centre on Substance Abuse (CCSA), being under the influence of marijuana affects a person’s abilities in the areas of tracking, reaction time, visual functions and divided attention which increases the risk for a crash. Yet, a student survey in Ontario found that nearly 1 in 10 (10%) of students in Grades 10 through 12 reported driving within one hour after using marijuana, which is a higher percentage than report driving after the use of alcohol.

    • Marijuana affects your ability to make decisions and divide attention. Research shows that driving slowly and taking safety precautions cannot make up for these impairing effects.
    • Some will argue that ‘experienced’ users know that they are intoxicated and will use strategies, such as slowing down, to be “extra careful”. But the CCSA reports these tactics may not be enough to make up for all the impairing effects of cannabis, especially mental functions like divided attention tasks and decision-making.
    • Even if a person feels they are able to drive, the risk of crash involvement remains high. This is especially true when marijuana use is combined with other substances, such as alcohol.
    • According to the Centre for Addiction and Mental Health (CAMH), marijuana is the psychoactive (meaning it affects brain function) drug most often found in dead and injured drivers, next to alcohol. Studies show that people who drive under the influence of marijuana are more likely to be involved in collisions, including fatal ones.
    • Youth may drive more often under the influence of marijuana than alcohol, because they believe that police officers cannot easily detect marijuana impairment if they are stopped. Not true. By law, if any police officer suspects a driver is impaired by any drug, he or she can demand the driver to complete a series of tests. The process is the same as for someone suspected of drinking and driving – and so is the penalty for refusing.
    • In 2008, the Criminal Code of Canada was changed to give police the authority to demand a driver suspected of being under the influence of drugs to submit to a Standardized Field Sobriety Test, to participate in an evaluation of drug influence by an officer trained in the Drug Evaluation and Classification program (known as a Drug Recognition Expert – or DRE) and to provide a sample of blood, breath or oral fluid to determine the type of drug(s) used.
    • Halton Regional Police have trained several officers to be Drug Recognition Experts (DRE) who are able to decide whether a driver is impaired by drugs.
    • DREs are trained to explain their findings to the judge in a trial, and judges see them as experts. These specially trained officers can go anywhere in Halton to help other officers who have pulled a driver over on the road. If the DRE officer decides the driver is impaired by drugs, the driver will be charged with the same offence a drunk driver would be charged with. The penalties can include driver’s license suspension and/or fines and a possible jail sentence.
Driving High

Why can drug tests for Marijuana use give a positive result long after the effect of the drug has worn off?

That is because THC is fat soluble. This means that in order for the body to break down the THC it has to dissolve in fat. This process takes more time than substances that break down in water. If someone uses marijuana again before the body has had the time it needs to break down the THC (3 days) the THC begins to build up in the fat tissue and the body never has the chance to clear out the THC entirely.

Drug Recognition Experts

In the above video an officer from Detroit Michigan takes reporters through the steps taken by specially trained Drug Recognition Experts.

Xperiment.ca Cannabis and Driving

The Canadian Centre on Substance Abuse would like to thank the following organizations for permission to use their videos: Above the Influence (US), MADD Canada, Ontario Students Against Impaired Driving, Region of Peel Public Health, New Zealand Department of Transport, THINK! Education (UK Department for Transport), Transport Accident Commission (Victoria, Australia)

Driving High
Driving High

Marijuana affects co-ordination and makes it harder to concentrate and react. This can increase the risk of injury if marijuana is used before skate boarding, biking or other sporting/recreational activities.

Additional Resources