Snow and slippery conditions were causing havoc on southern Saskatchewan highways on Friday.

Traffic was blocked for hours on the Trans-Canada Highway when a semi-truck rolled and jackknifed near Moose Jaw.

In the morning, four other vehicles ended up in the ditch on the Trans-Canada and drivers were being warned to check the Highways Hotline before venturing out.

"We do have some areas where we have snow drifts," Highways Ministry spokesperson Kirstin Leatherdale said.

"The temperatures are a little warmer and the highways are getting wet, and in those situations the snow will stick to the highway and the snow will accumulate."

The Regina Police Service was telling motorists to clear snow and ice from their cars, to give themselves more time to get to their destinations, to drive slowly and to not follow traffic too closely.