Juan Unger, 48, was driving home Tuesday afternoon in his Hyundai Accent and exited a highway at 25 mph, the Ottawa Sun reported.
Ahead on the ramp, Unger said he saw something black and assumed it was a tarpaulin or rug.
He told the Sun he had cars on both sides of him and couldn't swerve.
Although he slowed down, it was too late and the car plunged nose-first into the sinkhole, leaving only the tip of the rear bumper visible.
"My immediate thought was I hope I don't get killed or crushed or horribly injured," he said. "The car went vertical ... I was hanging from the seat belt."
Unger told the Canadian Broadcasting Corp. he decided to climb out of the car with the fear of being run over or falling even further down.
Other drivers who had stopped helped hoist him out of the hole, the CBC said.
Unger suffered only scrapes, the reports said.
Maintenance workers told the CBC a rotting 12-foot sewer pipe had caused the sinkhole.