Forecasters said that after plunging overnight temperatures - down to -3C in the South and -6C in Scotland - frost this morning will turn many wet and slushy roads into potential death traps. Fog, some of it freezing, is expected to add to the danger.
'Drivers are being lulled into a false sense of security by the gritting. Drivers must remember that braking is impaired. On some roads the grit is freezing over', a spokesman for the AA said.
Icy conditions have caused a spate of accidents. In Essex, police reported 68 accidents in a three-hour spell - one every two-and-a-half minutes. In Hertfordshire, more than 150 cars were found abandoned.
Driving conditions are expected to get worse: a new belt of rain will be moving in from the West today. That, combined with thawing snow and ice, will make driving conditions even more treacherous, the London Weather Centre said. The rain could also bring floods to northern areas.
In the South-east, work continued yesterday to tackle floods that have forced many people out of their homes and left farmland under water. The National Rivers Authority's flood defence stations on the Somerset Levels are pumping about 1 billion gallons of water a day into the sea.
The authority said that Exeter was being protected from the river Exe by a pounds 20m flood defence scheme diverting 950 million gallons of water daily into special channels.
In West Sussex, a red flood warning - indicating that properties are at risk - remained on the river Lavant in Chichester, which burst its banks two days ago. About 40 homes were evacuated on Thursday night. Floods closed the A27 east of Chichester yesterday, where the water was 4ft deep in places, and led to the cancellation of funerals at the town's crematorium.
A fleet of 10 'Green Goddess' fire engines from a civil defence centre were being used to pump the water along 1.5 miles of hose into the sea. Ten more are expected to join the operation, which could go on for another two weeks.
An NRA spokeswoman said that 131 flood warnings were still in force, compared with 155 on Thursday, including four red flood warnings.
In Dorset, homes were evacuated after experts detected a movement in land above them. Engineers spotted the shift while working on Ministry of Defence land near Portland. It is thought recent torrential rains might have had an effect.
Schools across southern England were forced to close. On the Isle of Wight, where there was heavy snow, 10 schools turned pupils away; seven schools closed in Bedfordshire, three in Hampshire and at least two in Hertfordshire. In Gloucestershire, a dry ski centre had to be closed because of the snow.Reuse content