Cannabis Impairs Driving

Like all drugs, cannabis has effects on the brain that affect driving. It causes a decrease in vigilance and concentration, slower reflexes, poor coordination, longer reaction times, and impaired judgment.

When driving under the influence of cannabis, you could: 

  • Fail to notice road signs 
  • Veer off the road
  • Have difficulty maintaining a constant trajectory
  • Pass other vehicles in an unsafe manner
  • Take too long to brake
  • Have difficulty reacting in the case of an emergency  

Drugs at the wheel can be detected

Police officers are trained to detect drivers who are “high” regardless of what they've taken.

Physical coordination tests

Unlike with drinking and driving, police officers do not use a device to detect how much drugs you have taken. Rather, they will have you go through a series of tests by the side of the road in order to determine your ability to drive.

  • Eye-movement test (follow-a-pen test)

    The police officer will have you follow a pen with your eyes in order to detect the presence of nystagmus (involuntary, jerky eye movements).

  • Walking test (walk-and-turn test)

    The police officer will ask you to walk on a straight line and turn around.

  • Balance test (one-leg stand test)

    The police officer will ask you to keep your balance while standing on one leg and counting out loud.

While these tests may appear banal, they are difficult to pass if you are under the influence of drugs. If you fail these tests, the police officer will arrest you and take you to the police station where you will have to undergo other tests.

Drug recognition experts

These are police officers who conduct another series of more extensive tests at the police station.
Among other things, they will measure or examine:

  • your pulse, your body temperature and your blood pressure
  • your eyes, in particular the size of your pupils
  • the insides of your nostrils and mouth
  • your muscle tone. Depending on the drug that was consumed, a person's muscles may be either more rigid or more relaxed
  • your arms and neck, in order to find any possible injection sites

You will also be required to provide a sample of a bodily substance (e.g. urine).

Drug-impaired driving is a crime, just like drinking and driving

You can be arrested and convicted under the Criminal Code if your driving ability is impaired by drugs, even if you haven't had a drop of alcohol. The penalties are the same as those for alcohol-impaired driving:

  • A $1,000 fine (minimum)
  • A criminal record
  • No licence for 1 year (minimum)
  • Program to assess and reduce the risk of a repeat offence
  • Prison (for a 2nd offence or in the case of an accident)

Don't mix!

Combining drugs and alcohol greatly increases your risk of a car accident. It makes an explosive cocktail that has a huge impact on your driving by multiplying the effects of all substances involved.

Having care and control – What is that?

If your faculties are impaired by alcohol or drugs, the law doesn’t just prohibit you from driving a vehicle, but also from having care or control of a vehicle. Here are some examples of acts that may result in the same consequences as driving while impaired:

  • Being seated in the driver’s seat, even if the vehicle is stopped.
  • Being in one’s car (even sleeping in the back seat) and having the possibility of starting the vehicle.
  • Being close to one’s vehicle (e.g. removing snow, putting things in the trunk or listening to the radio).