Quebec provincial police say a 47-car pileup on Highway 15 north near the Ste-Adèle exit left 64 people injured, as blowing snow and icy roads contributed to scores of accidents across southern and eastern Quebec.
Police said seven people are in serious condition in hospital, but their lives are not in danger.
The treacherous conditions have led to numerous accidents and many major highway closures as police and tow-truck operators scramble to clear the roads.
Laurentians traffic at near standstill
Highway 15 near Ste-Adèle reopened in both directions by late afternoon, hours after the late-morning chain-reaction accident. The rescue of as many as 33 people trapped inside their vehicles took hours, and firefighters had to use the Jaws of Life to remove people from wrecks.
Throughout the afternoon, travel to and from the Laurentians was at a near standstill, while another 30-vehicle accident at Mirabel closed Highway 15 for an extended period.
The highway has since reopened at Mirabel, but motorists who chose instead to try their luck on the parallel Highway 117 were instead stuck in a 10-kilometre long traffic jam on the alternate route.
Those who were able to make it north on the highway past St-Jérôme found themselves driving at a snail's pace once more, as a lane was blocked at the gateway to the Laurentians after a semi-trailer caught fire..
Closures east, south of Montreal
Elsewhere, other accidents led to road closures.
- East of Montreal, Highway 40 at Highway 343, near the town of St-Sulpice, was closed for an extended period after a multi-vehicle pileup. That reopened late in the afternoon.
- West of Montreal, Highway 40 near Rigaud has reopened after it was closed in both directions.
- Eastbound lanes have been reopened in Lévis, after a lengthy closure caused by a multi-vehicle collision.
- Highway 138 near Mercier has reopened after it was closed in both directions by a multi-car accident.
A police spokesperson said there have been close to 100 collisions in the region surrounding Quebec City.