St. Lazare resident Matthew Brown told CBC Montreal's morning show Daybreak that he was exiting from the eastbound Highway 40 on Friday when he spotted a large hole on the service road he was about to merge onto.
He said it was too late for him to react once he realized the size of the pothole.
Brown says he slammed on the brakes, but his car was thrown into the cement divider.
His car ended up flipped upside down on the side of the road, just after the Chemin Sainte-Marie exit.
"This is ridiculous, this could have killed me," he said.
Brown said the pothole extends nearly the full width of the off-ramp — measuring almost two metres across and 2½ metres long and close to 10 centimetres deep.
He said once he checked himself and realized he only had a few minor injuries, he went back to take a look at the pothole.
"First thing I did was I took some pictures of the car, the skidmarks on the road where my car had travelled and of course, the pothole itself."
On Saturday, Brown posted his story and the photos on an online car forum — Montreal Racing. Since then, the post has received over 11,000 views.
Kirkland Mayor John Meaney told CBC he wasn't aware of the accident and intended to investigate.
Because the service road is part of the provincial highway network, it falls under the jurisdiction of Transport Québec.
Ministry officials said they intend to do repairs this evening. In the meantime, road crews have drained the pothole and marked it with traffic cones.
The president of Quebec's Automobile Protection Association, George Iny, said his advice to drivers who find themselves unable to avoid a pothole is not to brake.
"You actually would want the wheels to continue rolling," Iny said. "One of the risks is if you apply the brakes in the pothole the wheels will come to a full lock."
Iny said he has heard of cars flipping after hitting potholes before — in Africa — but never on a Canadian highway.