With ice on the road, a jackknifed semi, and emergency vehicles in the ditches, Highway 11 was impassable northwest of Regina, the RCMP said Friday morning.
The Trans-Canada, ice-covered in sections, wasn't much better.
From Lumsden to Regina, Highway 11 was closed in both directions. Conditions were changing from hour to hour, so people were being advised to check the Highway Hotline before heading out.
Police were also warning that conditions were so bad, drivers who ignore the warnings and get into trouble may not get help very quickly.
On one section of Highway 11, which is the main route from Regina to Saskatoon, an RCMP vehicle and an ambulance slid off the road and got stuck in the ditch, unable to respond.
One RCMP vehicle that was parked on the site of the road got rear ended by a passing vehicle and is inoperable. There was nobody in the vehicle at the time.
Gravel trucks cannot get through because of the blocked roadway.
So far, there are no reports of injuries.
Conditions were also bad on the Trans-Canada Highway east and west of Regina.
East of the city, near the Pilot Butte turnoff, a semi was in the ditch early in the morning following a collision with a van.
CBC journalist Amanda Marcotte said the van was in the ditch with the semi, partially pinned under the big truck.
Conditions were extremely slippery at the scene due to ice, she said.
"It is literally a curling rink," Marcotte said.
She said police told her that no one was injured in the crash.