Driving with a joint behind your ear probably won’t land you in the joint, but you’ll likely score a fine.

“So every province I’ve looked at, you can’t have cannabis in your vehicle unless it’s stored in a closed or fastened container out of the reach of the driver,” said Eric Dumschat, legal counsel for MADD Canada. “It’s the same with alcohol – you just can’t have joints rolling around in the back seat just like you can’t have an open beer bottle inside the car.”

In Ontario, Bill 36 is the proposed update to several laws to address how the province will handle legal weed. If it passes, it will ban driving with an open bag of weed or loose joints in a vehicle once marijuana becomes legal to smoke this month.

But you would be able to carry cannabis in the car if it is “in its original packaging and has not been opened – or is packed in baggage that is fastened closed or is not otherwise readily available to any person in the vehicle,” Brian Gray, a spokesman for the Ontario Ministry of the Attorney General (MAG) said in an e-mail statement.

So, you’d be able to have an unopened bag of weed from the cannabis store in the front seat – just like you can have a sealed bottle of wine there now.

And, just like alcohol, you won’t be allowed to have it open – or consume it – in your parked vehicle either, even if you’re sitting in the back seat.

That’s because the proposed rules say you can’t have open weed in the car while driving or while in the care and control of your vehicle – in other words, if you have the keys and could drive.

The proposed rules would also apply to boats.

Ssome fines still being decided

Plus, you won’t be able to fill the trunk of your Malibu with Mary-Jane. Federal rules say you’re only allowed to possess 30 grams of dried weed in public. That includes your vehicle.

We didn’t get an immediate answer about the proposed penalties for having open weed in a vehicle in Ontario, but driving with opened booze within reach will cost you $175.

Everywhere else, the penalties will vary, but it’s usually a fine, even if harsher penalties are on the books, MADD said.

In British Columbia, for instance, the first offence is a fine up to $5,000, up to three months jail time, or both.

But the province said it expects to give tickets instead of prosecuting people with weed in the vehicle. The ticket amount for cannabis hasn’t been set, but the ticket for open liquor is $230, said Hope Latham, a spokeswoman for B.C.’s Ministry of Public Safety and Solicitor General, in an e-mail statement.

Don't vape and drive

And no, you can’t smoke or vape weed while driving – or while someone else is driving.

“Obviously you can’t be smoking a joint while you’re driving, just like you can’t be drinking a beer while driving,” Dumschat said. “You’d get pulled over and probably face criminal charges.”

In B.C., it’s illegal for anyone to use cannabis, in any form, in a vehicle, Latham said.

Ontario’s law would also ban passengers from smoking pot in a vehicle. But, the province has proposed an exception that would allow “non-smoking and non-vaping forms of consuming medical cannabis by a medical cannabis user who is a passenger in a vehicle or boat,” Gray said.