Overview

Driving a vehicle while you’re impaired by cannabis is illegal and dangerous. This includes cars, trucks, boats, snowmobiles and off-road vehicles.

You are not a safer driver when you’re high. Cannabis affects your judgment, coordination and reaction time, and increases your chances of being in a collision. In 2016, 74 people were killed in collisions involving a driver under the influence of drugs in Ontario according to police reports.

Barely high is still too high to drive – don’t risk your future or your life. Never get behind the wheel after using cannabis.

Zero tolerance for young, novice or commercial drivers

Just like alcohol, you are not allowed to have any cannabis in your system (as detected by a federally approved drug screening device) if you are driving and you:

  • are 21 or under
  • have a G1, G2, M1 or M2 licence
  • are driving a vehicle that requires an A-F driver’s licence or Commercial Vehicle Operator’s Registration (CVOR)
  • are driving a road-building machine

The penalties for violating Ontario’s zero tolerance law include licence suspensions and financial penalties. Repeat offenders face longer suspensions and additional consequences such as mandatory education and treatment programs.

Medical cannabis users

You will not be subject to the zero tolerance drug requirements. You may still face penalties and criminal charges if your ability to drive has been impaired.

How to avoid impaired driving

Impairment from cannabis begins almost immediately and can last up to 6 hours or more, depending on factors such as THC levels and how it is consumed. The effects can last longer if you’re a new user, have consumed a lot or have combined cannabis with alcohol.

Since the effects of cannabis vary, there is no way to know exactly how long to wait before it’s safe to drive. Even if you think the high has worn off, your ability to drive may still be impaired.

The best way to avoid impaired driving is to not take a chance. Plan another way home:

  • have a designated driver
  • use public transit
  • call a friend or family member for a ride
  • call a taxi or ride share
  • stay overnight

Enforcement and penalties

Police have tools and tests to detect impaired drivers, including roadside drug screening equipment and sobriety tests.

If a police officer finds that you are impaired by any drug or alcohol, you will face serious penalties, including:

  • an immediate licence suspension
  • financial penalties
  • possible vehicle impoundment
  • possible criminal record
  • possible jail time

Learn more about Ontario’s drug-impaired driving penalties.

Transporting cannabis

Similar to the rules for alcohol, it is illegal to transport cannabis in a motorized vehicle (such as a car or boat) if it is:

  • open (“unfastened”) and not in its original packaging
  • not packed in baggage and is readily available to anyone in the vehicle

It is illegal to take cannabis across the Canadian border. For information on transporting cannabis in an airplane within Canada, check with your airline.

Updated: July 21, 2021
Published: February 20, 2019