It was a very dangerous and slippery situation on Highway 400 south of Barrie, Ont., Friday.

The northbound 400 was closed between Highway 89 to Innisfil Beach Road, south of Barrie, Ont., after icy roads triggered two separate multi-vehicle crashes, but has since reopened. The stretch of highway was closed for around five hours.

The freezing drizzle has left a thin glaze of ice on the 400, which resulted in several vehicles spinning off the road and into each other.

There were four crash scenes along that stretch of roadway — one involves four vehicles, including one that flipped onto its roof. A woman is in hospital with life-threatening injuries.

“There [was] a tractor-trailer that’s in the ditch covering about two northbound lanes,” a 680News listener named Don said.

Kevin Frankish of Citytv’s “Breakfast Television” said he was driving just south of Barrie on the 400 when the temperature dropped just as wet snow and freezing rain moved in.

Meanwhile, the rest of the GTA will get an early taste of winter driving as snow moves in Friday afternoon.

The forecast calls for between 1-2 centimetres of snow for Toronto and most of the GTA, but areas near Oakville, Burlington and Hamilton could get 2-5 centimetres or more due to lake enhancement.

The snow is not expected to stay on the ground very long. According to the forecast, temperatures in the GTA will be around 6 C.