Cannabis and Driving in Ontario

Cannabis slows reaction time, affects coordination and makes it harder to judge distance and speed. Those are exactly the skills you need behind the wheel. That's why Ontario and federal law treat drug-impaired driving as seriously as drunk driving.

Impaired is impaired

Driving while impaired by cannabis, alcohol or any other drug is a criminal offence in Canada. Police can do roadside screening, and a driver found to be impaired faces:

• an immediate licence suspension
• financial penalties
• possible vehicle impoundment
• possible criminal charges, a criminal record and jail time

There's no reliable way to "feel" when THC has worn off enough to drive, and it can stay in your system long after the high fades. Edibles in particular can affect you for many hours. If there's any doubt, don't drive.

Zero tolerance drivers

Some Ontario drivers can't have any cannabis in their system, as detected by an approved drug screening device. Zero tolerance applies if you:

• are 21 or under
• hold a G1, G2, M1 or M2 licence
• drive a vehicle that requires an A to F class licence or a Commercial Vehicle Operator's Registration (CVOR)
• drive a road-building machine

For these drivers, a positive test means penalties even if they don't seem impaired. Repeat offences bring longer suspensions and mandatory education or treatment programs.

People who use medical cannabis aren't covered by zero tolerance, but they can still be charged if their ability to drive is impaired.

No consuming in a vehicle, ever

You can't smoke, vape or eat cannabis in a car, truck or boat that's being driven or will be driven. That applies to passengers too. Hotboxing in a parked car before driving home is exactly what this rule targets.

Transporting cannabis legally

You can carry cannabis in a vehicle or boat, but it has to be:

• in its original packaging, unopened, or
• packed in baggage and not readily available to anyone in the vehicle

In practice: keep it sealed, in the trunk or in a bag that's packed away, not in the glovebox, console or a cupholder.

Boats count too

Ontario's rules cover boats as well as cars, so you can't consume on a boat that's being driven. On a lake near Sudbury in July, that's an easy one to forget. An anchored boat with permanent sleeping and cooking facilities is treated more like a residence.

Crossing the border

Taking cannabis across the Canadian border is illegal, whether you're driving to Michigan or flying anywhere outside Canada. Don't bring it, and don't leave any in the car.

Plan the ride before you start

• Decide how you're getting home before you consume anything.
• Edibles last longer than you think. If you had one in the evening, you may not be fit to drive later that night. See How Long Do Edibles Take to Kick In?.
• Mixing alcohol and cannabis increases impairment.
• Next morning: if you still feel any effects, wait.

For the rest of Ontario's rules, from the 30-gram limit to home grow, see Ontario Cannabis Laws: What Adults Need to Know.