Snow gave way to ice as overnight temperatures dropped like a stone in the Bristol area, causing further problems today for drivers and those using public transport.

Freezing conditions turned many roads into ice rinks as the melting snow from yesterday left them in a treacherous state.

Side roads were the most severely affected but there were also problems on the motorway network, with only two lanes open on stretches of the M5 and M4.

Drivers out and about early on the M5 found lane three closed in both directions between junction 16 at Aztec West and Taunton. There were also only two lanes open between Falfield, near Thornbury, and Stroud. Similar problems affected the M4 from junction 18 at Tormarton into Wiltshire.

Only one of the two Severn crossings was open as a result of ice falling from gantries onto vehicles. For much of yesterday both bridges were shut after five windscreens were shattered by ice.

The Severn Bridge, which eventually opened late on Friday afternoon, remained in use through the night and into today but the Second Severn Crossing remained shut to all traffic. There were inspections being carried out throughout today.

Rachel Whitelock at the Highways Agency said: "There were huge pieces of ice coming down but fortunately no-one was hurt."

Bus operator First said it was working hard to run bus services wherever possible, with some routes being covered as normal, while other services were not running or had to be curtailed due to the road conditions. The situation was being reassessed throughout the day.

At Bristol International Airport, a full schedule was running but passengers were warned there could be some delays as it dealt with the aftermath of problems yesterday.

Bristol City Council said although a slight thaw was expected today, road and pavements were due to freeze again tonight.

Major roads had been salted and were running relatively well but minor roads remained hazardous.

Spokesman Simon Caplan said: "Bristol's main roads were salted between 6pm through to 10pm on Friday night and again from about 4am to 7am on Saturday morning. The major routes are clear.

"We have received a limited supply of new salt overnight but need to use this sparingly over the next few days to cope with continuing weather conditions.

"The council has seven gritting vehicles operational at any one time. Minor roads cannot be salted and some remain very hazardous due to black ice. Talbot Road in Knowle has been closed by police and there is the possibility of other minor roads being closed by the police if there is a serious safety risk."

He said a decision about Night Flyer buses tonight and into tomorrow morning would be made later today, while park and ride services at Portway and Long Ashton were operating with a slightly reduced service today.

Services at the A4 Bath Road, Brislington, were suspended, with a decision being taken later today on whether to start running them.

The council-supported 500 bus service, which provides a circular route around the city centre, was operating as normal.

But bin men were unable to get out to clear the backlog of rubbish collections and it is hoped to resume collections next week.

But household waste and recycling centres in Avonmouth and St Philips were open as usual, along with leisure centres and pools.

Mr Caplan said there had been delays in getting home care and meals on wheels to people who lived in the worst affected areas but staff were walking where necessary to reach those who relied on the services.

During the night, fire fighters were called to help a driver whose Jaguar started to slip down a hill between Clifton and Hotwells.

The man was parking in steep Ambra Vale just before 1am today and couldn't get the car close to the kerb as it kept slipping.

He called fire fighters, who walked up the hill and put salt down so the car could be parked safely.

Crews were also called to Charborough Road in Filton at 10.45pm when a car slipped on ice and went into a garden wall. No-one was hurt.

On the railways there was a train fault on the Bristol Temple Meads to Severn Beach line, leading to a limited service.