Heavy snowfall and poor visibility led to a series of crashes on Highway 400 between Barrie and Waubaushene Monday, snarling traffic on the roadway.

Ontario Provincial Police said a number of collisions involving multiple cars occurred on the southbound lanes of Highway 400 near Duckworth Street. The crashes caused a backup stretching north to Line 3 in Oro Township.

“We’ve got a couple of major collisions on the go right now,” OPP Sgt. Peter Leon told CP24 Monday afternoon. “I’m not aware of any serious injuries. However we are experiencing a significant snowfall in this area with heavy snowsqualls and blinding visibility.”

Springwater Firefighters tweeted they were called to another crash involving two vehicles in the southbound lanes at Highway 400 and Highway 11.

Leon said a collision happened there at around 3 p.m. due to blinding snow.

The collisions occurred as a winter weather travel advisory remains in place for Barrie, Collingwood and Hillsdale.

“Flurries at time heavy through the region will give reduced visibility and combined with cold temperatures will make driving difficult especially early this evening,” Environment Canada said in its advisory.

Leon said AOPP are advising people to delay travel if possible until the weather clears up.

“Anybody who may be considering heading back south towards the city, we’re going to strongly suggest that you delay your departure,” Leon said.

A CP24 viewer said another series of collisions occurred at Highway 400 and Highway 12 in Waubaushene. The viewer said she could see as many as two dozen vehicles in the ditch.

The southbound lanes of Highway 400 were closed at Quarry Road north of Waubaushene due to the crashes. The highway reopened at around 5:30 p.m.

Even with some of the major collisions cleared, traffic has slowed to a crawl on parts of Highway 400, with slick roads and heavy blowing snow making driving conditions hazardous.