Three people were injured when two cars collided in the eastbound lane of Highway 417 near the Carp Road late Saturday night.
One car rolled over several times before coming to rest on its roof in a ditch, according to paramedics who were on the scene.
The other car travelled another 60 metres down the highway after the crash, they said.
Ottawa firefighters had to cut open the car in the ditch to get out the driver and two passengers.
A woman in her 50s was driving the car. She and her two elderly passengers, a man and a woman, were all treated for minor injuries. All three were taken to hospital in stable condition.
The driver of the other car refused assessment by paramedics, but was apparently uninjured.
Ontario Provincial Police are investigating.