The late winter storm that covered Toronto in about 15 centimetres of snow has left an icy mess on the roads leading to hundreds of collisions overnight and into Thursday.

There were more than seven tractor-trailers between the Halton border and Toronto on Highway 401 between 4: 30 a.m. and 6 a.m. Thursday — two of which jackknifed at Winston Churchill and Highway 401 at 5 a.m. in each direction.

At around 12 a.m. an SUV rolled over on the Dixon Road off ramp from the westbound 401. A tractor trailer ended up in a ditch at Erin Mills and the westbound 401 at around 4 a.m.

tractor trailer crashes

There were many tractor-trailers collisions early Thursday, two of which jackknifed at Winston Churchill and Highway 401 at 5 a.m. in each direction. (Tony Smyth/CBC)

Crashes due to icy conditions are often the result of people driving too fast for the winter conditions, according to police.

Environment Canada said Wednesday’s storm was the worst March storm in the past three years.

The cleanup continues into Thursday. Trevor Tenn, with the city’s transportation services, says it will be at least 12 p.m., before most of the streets are cleared.

“It takes about 16 hours after the storm has ended to plow the local streets,” Tenn said, adding it would be helpful if people held off on calling 311 until the plowing has been done.

And the ice isn’t expected to melt yet, as the city remains under an extreme cold alert this morning.