Highway 400 was reopened shortly before 4 p.m., Thursday, following a 50-vehicle pileup south of Barrie.
Highway 400 is now open again to traffic between Highway 88 and Innisfil Beach Road, OPP Sgr. Kerry Schmidt said.
The multi-vehicle crash included approximately 50 vehicles and around a half-dozen transport trucks.
"Fortunately, no reports of injuries," Schmidt said.
It was havoc on the highway earlier in the afternoon, as Highway 400 was closed northbound at Highway 88 and southbound at Innisfil Beach Road due to a series of crashes.
"We're dealing right now with a multi-vehicle pileup on Highway 400, mostly in the northbound lanes near (Innisfil Beach Road), just south of Barrie," Schmidt said earlier this afternoon.
"Conditions are not great there and they're probably not great in many places in the GTA and surrounding (area)," he added.
Schmidt said there was also an incident in the St. Catharines area where a motorist was struck after exiting their vehicle following a collision. He said the did not believe the person suffered critical injuries.
"There are some very serious situations going on right now," he said. "It's going to be a busy day."
Schmidt urged people involved in a collision to get their vehicle safely to the side of the road before getting out to inspect the damage.
"If you're not able to drive your vehicle or move your vehicle, then stay inside your vehicle so you have a safety cage around you," the sergeant added.
Schmidt also urged motorists to turn on their full headlight system and to take your time.
“Tomorrow, as conditions continue to potentially be like this, if it freezes and thaws, we could have pieces of ice flying off vehicles which can be very problematic, as well," he said.
