Cannabis-Impaired Driving


Driving after using cannabis is illegal and it more than doubles your chance of motor vehicle collision. It is just as bad as drinking and driving. If you choose to use cannabis, be smart about it and don’t drive high. Be informed of how it impairs your driving ability to protect yourself and other drivers on the road.

Plan to help everyone get home safely:

  • Have a designated driver.
  • Call a friend or loved one.
  • Call a cab or ride-share.
  • Use public transit.
  • Stay the night.

The THC in cannabis affects your driving ability in the following ways that make it dangerous to drive:

  • impairs concentration and short-term memory,
  • distorts perception of time and space,
  • slows reaction time,
  • reduces your co-ordination of body movements,
  • lowers the ability to track moving objects (such as other cars or bicyclists),
  • lowers the ability to respond to more than one thing at a time (such as watching your speed, lane position, distance between you and another car, pedestrians or bicyclists – all at the same time),
  • leads you to weave in and out of lanes, and
  • makes it difficult to keep a constant speed.

For more information, visit Don’t Drive High

You should wait at least six hours after using cannabis to drive, and it’s best to not use it at all if you plan on driving or operating machinery.

It can be more difficult with cannabis than with other substances like alcohol to determine when you are impaired and when you are safe to drive. Depending on the form of cannabis used, the THC concentration, and how it affects you, the effects could be more immediate or delayed and can last for a shorter or longer time.

You can also lower your risk of impairment by using lower THC concentration cannabis, not using it every day, and not using it with alcohol.

Driving after using cannabis is illegal. Police can legally request a driver to undergo testing to confirm impairment by drugs (illegal, prescription, or over-the-counter medications) and you will be subject to serious penalties. It is taken as seriously as driving impaired by alcohol.

For a full description of Ontario’s new laws for drug-impaired driving, including zero tolerance for young, novice and commercial drivers, and associated penalties, visit the Ontario Ministry of Transportation

Drivers age 21 or under, novice drivers (drivers who have a G1, G2, M1, M2, M2-L or M2-M licence), and commercial drivers are prohibited from having any cannabis or other drugs in their system and face penalties and potential criminal charges. That means that Ontario has a zero tolerance approach to both alcohol and drugs for these drivers.

It is illegal to:

  • drive impaired after using any form of medical* or non-medical cannabis,
  • smoke or vape cannabis in a vehicle or boat being driven or under someone’s care or control,
  • use any form of non-medical cannabis in a vehicle (edibles, extracts, smoked, vaped, etc.), or
  • use any form of medical* or non-medical cannabis if a vehicle is under your care and control.

*If a police officer is satisfied that you are legally authorized to use cannabis for medical purposes, you will not be subject to Ontario’s zero tolerance drug requirements for young, novice and commercial drivers. However, you can still face penalties and/or criminal charges if a police officer finds that your ability to drive is impaired. Even if you have been authorized to use cannabis or another drug by a health care professional, it is your responsibility to ensure you are not impaired while driving.

For a full description of Ontario’s new laws for drug-impaired driving and penalties, visit the Ontario Ministry of Transportation

Adults over 19 can legally possess and transport up to 30 grams of dried cannabis or 450 grams of edible products but it must be out of reach. Containers that have been opened must be stored in the trunk.