Freezing rain and ice pellets continue to make for a messy drive around the GTA.

A freezing drizzle advisory from Environment Canada remained in effect Wednesday night after sheets of freezing rain and ice pellets swept over the city for much of the day.

That freezing drizzle is expected to continue overnight and into Thursday morning.

[Full weather forecast can be found here]

Speaking with CP24 on Wednesday afternoon, Ontario Provincial Police Sgt. Kerry Schmidt said that the messy weather has already created “slushy and miserable” road conditions across much of the GTA.

He said that while salt trucks have been treating most major roads, the conditions are likely to deteriorate further as the freezing rain continues to fall this afternoon.

“The morning rush was very slow and I suspect the afternoon rush will be equally challenging for motorists,” he said. “Patience will be a virtue you are going to want to have. Just take your time, relax and realize that this is one of those days where it will take longer to get home.”

Schmidt said that there have been numerous collisions amid the messy weather, including a jackknifed tractor trailer on Highway 401 near Renforth Drive.

He said that conditions aren’t likely to improve for some time either.

“The salt is doing its work but anywhere where it is not salted it could certainly lead to icing, freezing conditions and slippery roads later on,” he said.

School buses cancelled

The inclement weather prompted school boards in Toronto, Hamilton, and the regions of York, Halton, Peel, and Durham to cancel transportation this morning.

A number of universities and colleges have also closed down.

[Full list of school cancellations, closures can be found here]

The University of Toronto's Mississauga campus was closed for the day while Ryerson University, Seneca College, George Brown College, The University of Toronto’s St. George and Scarborough campuses, Durham College and the University of Ontario Institute of Technology all opted to close as of this afternoon.

Canada Post says all mail delivery was also suspended on Wednesday afternoon due to treacherous conditions.

"We encourage customers to clear the snow and ice from their walkways, stairs, and driveways, to ensure safe access to the front door for both their visitors, as well as their mail carriers, when service resumes," a spokesperson said.

Salting to continue through the night

Salters were on standby at locations across the city beginning at 4 a.m. and have been busy throughout the day.

As of late this afternoon, a third round of salting on main roads was underway and the first round of salting on local roads was mostly complete, according to the city’s winter operations department.

The city has said that the second round of salting on local roads will begin overnight Thursday and continue for up to 24 hours.

“This storm didn’t happen at the best time for us so this cleanup is going to take us into the p.m. rush hour. Please give yourself some extra time, slow down and drive to the conditions of the roadway,” Mark Mills, the superintendent of road operations for the City of Toronto, told CP24 on Wednesday afternoon. “Although it looks like Mother Nature may have the upper hand sometimes we will get these roads in good shape.”

Mills said that staff with the winter operations department are patrolling the roads so that the response to the storm can be modeled on current road conditions and not just the forecast

He said that approach is particularly necessary in light of the constantly changing conditions.

“We have seen little bit of everything today. It started out with ice pellets, that turned to snow and then we saw some rain and now a little bit of freezing rain,” he said.

The TTC is replacing streetcars with buses along the 506 Carlton and 512 St. Clair routes due to the weather.