SCOTLAND'S already treacherous driving conditions are set to get even worse after experts warned that the nation's roads will be left with up to a third more potholes as a result of the big freeze, The Scotsman can reveal.
• Pothole repairs will add an extra burden to council budgets. Picture: TSPL
Temperatures have been so low for so long that water in cracks in the roads is freezing and expanding, causing the surface to break apart.
And today, as thousands of Scots prepare to return to work after the festive break, the true scale of the problem is set to become apparent after two weeks when the roads have been quiet.
The crisis is expected to add tens of millions of pounds to the country's huge road maintenance backlog and increase claims for vehicle repairs.
The "freeze-thaw" problem is likely to create a major new headache for cash-strapped councils, which have already had to increase winter clearance spending as they struggle to keep roads open.
The fears came as ministers acted to avert a salt shortage at some councils, with Fife receiving emergency stocks yesterday after almost running out.
The longest cold snap for several decades is expected to continue into next week, with temperatures in Edinburgh and Glasgow falling to –6C tomorrow night, and to –11C in Braemar and –13C in Aviemore. The coldest places yesterday included Dunfermline and Livingston at –10C.
The Automobile Association said an increase in potholes would be a major challenge for councils. AA president Edmund King said: "Early indications are that winter road damage could result in at least one third more potholes than normal.
"This will lead to one-third more expenditure on reactive road maintenance and put many cash-strapped local authorities under more pressure. In normal years we tend to see more potholes around March, but due to the cold spell hitting Scotland earlier and more severely, the potholes are appearing sooner than normal.
"On top of the extra bill that highways authorities will have for the extra salt required, they will come under pressure to fix the potholes and could be hit by legal claims for compensation from road users for damage to their vehicles or personal injury claims."
The prediction could add several million pounds to repair bills for councils such as Edinburgh, which spends some 20 million a year on roads and pavements. Across Scotland, the extra cost could run into tens of millions, adding to the country's 2 billion road maintenance backlog.
Derek Elder, Scotland director of the Institution of Civil Engineers, said: "The resilience of the road network could not survive another month of constant snow and ice – there would be severe damage to road surfaces."
Scotsman readers have reported a significant increase in potholes, including in the outside lane of the M9 between Edinburgh and Stirling, and in Glasgow city. The Royal Automobile Club Foundation expressed concern at such damage on motorways, which are maintained by firms for the Scottish Government's Transport Scotland agency.
Spokesman Philip Gomm said: "Scottish motorists will be used to enduring potholes on minor roads, but allowing the surfaces of trunk roads to deteriorate is a bad sign. These highways are essential for the country's economic wellbeing, and unless Transport Scotland dedicates resources to mending them now, they will simply be storing up major problems – and huge bills – for the future."
Neil Greig, policy and research director of the Institute of Advanced Motorists, said the big freeze would expose the shortcomings of councils failing to maintain roads properly.
He said: "If you patch rather than repair, it won't last as long."
Several councils, including East Lothian and Western Isles, admitted they faced major pothole problems, while Moray expected "widespread" damage.
Snow and ice continued to cause disruption yesterday, with several roads closed in Aberdeenshire and Edinburgh-Glasgow trains halved to half-hourly.
Transport Scotland said: "Following a sustained period of adverse weather, it is normal for our operating companies to observe an increase in numbers of potholes recorded." He added "priority defects" should be made safe immediately, and "permanently repaired" within four weeks.
Islay Airport is closed because of ice on the runway but was expected to open at around 11am. Edinburgh, Glasgow and Aberdeen airports are all disrupted.
On the railways East Coast Main Line travellers are delayed, Edinburgh and Glasgow Central trains limited and buses are replacing trains between Edinburgh and Motherwell.
Passengers going between London and Glasgow Central on the east coast are being advised to take Virgin Trains' West Coast trains instead. Signalling problems in Carstairs, Lanark, caused delays on Virgin and First TransPennine Express trains.
ScotRail is advising passengers not to travel from Glasgow to Kilmarnock, Ayr and Stranraer because of the cold weather. And trains between Dalmuir and Springburn, Milngavie and High Street (Glasgow)/Bellgrove, and between Kirkwood and Whifflet were cancelled.
Buses are running between Inverness and Aviemore to replace rail services because a derailed freight train is blocking the track.
In Aberdeenshire all swimming pools, leisure centres, libraries and community centres were closed.
HIGHLAND: 30,000 tonnes of salt used in last two weeks – more than whole of 2006-07
MORAY: Ten-day reserves to be replenished at end of week. 'We may have to have an armed guard to keep other councils getting their hands on it,' a spokesman jokes
W/DUNBARTONSHIRE: Down to 'critically low salt levels'. Over 1,000 tonnes a week spread – ten times usual amount
S/LANARKSHIRE: Shipload of 5,000 tonnes of salt on way from north Africa or Mediterranean. Daily deliveries from northern England
GLASGOW: Only most heavily used pavements cleared. Grit mixed with salt to economise
ARGYLL & BUTE: Salt stocks 'very low' but 'we should survive', says spokesman
RENFREWSHIRE: Salting limited to main routes. But new delivery expected today
ABERDEEN: Cargo ship carrying 4,500 tonnes of salt arrived yesterday. Enough for ten days
FIFE: Emergency shipment of 250 tonnes received from Perth & Kinross and Scottish Government after stocks ran out
EDINBURGH: Insufficient staff to clear minor roads and pavements
MIDLOTHIAN: New salt delivery yesterday
BORDERS: Drivers urged not to travel 'unless absolutely essential'. Salting limited to A roads. 'Very limited' stocks
Heavy snowfalls forecast for Scotland, with up to 10cm more falling in Highlands
Scotland forced to buy road salt from Africa as stocks dwindle
Jenny Fyall: Long-term trend is to warming
In pictures: Curlers take advantage of frozen lake