Highway 400 has reopened south of Barrie following several collisions this afternoon.

OPP Sgt. Kerry Schmidt said blowing snow created dangerous driving conditions for motorists along a busy stretch of the highway.

Highway 400 was shut down in both directions between Highway 88 and Innisfil Beach Road at around 1:30 p.m.

Schmidt said several crashes were reported, including a 20-car pileup.

"Other vehicles are spinning out of control. We have several jack-knifed transport trucks and other issues that are blocking the highway," Schmidt said.

"Heavy tows, light duty tows are all assisting right now, getting these vehicles off the highway."

No serious injuries were reported.

As of about 3 p.m., all vehicles involved in the collisions had been removed from the highway and Schmidt said the conditions had improved substantially since the snow first began to fall.

"Right now, the snow has moved off the 400," he said.

"The plows have been through, the salters are down… the conditions are much better than they were an hour ago."