Earlier heavy snow and ice continues to be a problem on many of Somerset's roads.
Two lanes of the M5 are now open in both directions between Gordano services and Exeter - but many minor roads remain impassable because of ice.
Somerset County Council said about half of A roads and other major routes had been well salted.
But a spokesman said some heavy goods vehicles were having problems on routes with gradients causing delays.
On Sunday night temperatures fell to -13C in places and up to 20cm (8in) of snow fell.
The M5 was down to one lane in either direction south of Bridgwater until lunchtime on Monday.
BBC weatherman Richard Angwin said although it would be less cold than Sunday night the county would remain extremely icy.
"Ice and compacted snow will continue to be a hazard with no sign of a thaw on Tuesday."
Bristol Airport remained open throughout Monday but passengers were warned there may still be disruption to flights.
A spokesman added passengers should allow extra time for their journeys to the airport.
Bus operator First Bus said all services operating out of Bridgwater, Yeovil and Taunton remained suspended on Monday evening.
Many services in Wells are also suspended and passengers should check with the company website.
Avon and Somerset Police advised people to keep to major routes and "be wary of sat-navs suggesting... untreated or rural roads".
The snow and ice has also been blamed for an increase in the number of casualties being treated at a Somerset hospital.
Musgrove Park Hospital, in Taunton, has reported 50 weather-related fractures in two days - normally it is about 20.