A major winter storm is creeping into southern Ontario and will continue to make its way to Atlantic Canada as well.
Upwards of 20 cm of snow is possible in some places, which has city crews on alert.
Officials are warning motorists to be mindful of snow plows as operators will be working to keep the roads clear and safe.
"If you do see our snowplows out there, be cautious and stay well back," says Toronto snow plow operator Gord Troughton. "Definitely do not ever try to pass a group of snow plows because it's very dangerous for yourself and for the drivers."
As road conditions deteriorate, it's important to keep a safe distance from the plows.
"Drivers should be staying back at least six to eight car-lengths. We would expect that in all conditions, but definitely when the weather is snowy or we happen to see black ice conditions,” says Myles Currie, Director with Toronto's Transportation Services Division.
Plows travel at a speed that's most effective for removing snow and in some cases they're also applying salt.
"Remember, just because you can see them doesn't always mean the can see you as snow plows have very restricted sight lines," adds Currie.