At least thirty vehicles were involved in a pileup on Highway 40 Monday morning, about 70 km west of Quebec City.
Officials had closed the highway while they investigated but Ministry officials confirmed the westbound lanes of the major artery opened at 8:40 pm ET.
At least 20 people were hurt in the chain-reaction crash, including one elderly woman whose injuries police describe as serious.
According to witnesses, icy roads sent several cars and tractor trailors veering off the road, landing in ditches.
Police believe winter weather and poor road conditions are likely the cause of the accident.