Gritters treat roads across Devon overnight
Gritters have been out across much of Devon overnight to treat roads as temperatures reached -9C in parts of the county.
Widespread snow caused problems on Thursday, particularly in the north and east of the county and the South Hams.
Devon County Council said gritters were out at 0400 GMT.
However, it added that Ivybridge, Newton Abbot and Exeter were not being treated because there was enough salt on roads in those areas.
More than 400 tonnes of salt has been spread on the county's roads in the past 24 hours in an effort to keep the network clear.
The council said the lowest temperature it had recorded was minus -9.2C in Yarcombe, near Honiton.
However, one BBC Radio Devon listener reported temperatures as low as -12C.
Highways managers said they were still concerned about ice forming.
Devon County Council's highways operations manager, Chris Cranston, said: "As soon as you get down to those sort of temperatures, the effect of salt reduces.
"It gets more and more difficult to start depressing the freezing point of the ice, so it does start becoming more challenging at those temperatures."
First Bus said its services in Plymouth, north Devon and south Devon were operating but could be subject to delays.
The council has a website to inform parents of any school closures.
The county was due to have a very cold, icy start, the Met Office said.
Rain was due to push in from the west, it added.