SCOTLAND's roads are pockmarked with the highest number of potholes in the UK and would stretch to a combined depth of nearly four miles, according to a new study.

New research has revealed that a total of 154,310 potholes were reported to Scottish councils last year – around 16,000 more than the next worst-hit region, the South-west of England.

It means Scottish motorists are reporting around 423 cavities each day, three times more than counterparts in London.

The figures, collected by insurance firm, come as estimates suggest Scotland is facing a roads maintenance shortfall of £2.25 billion and with councils facing further financial challenges, the figure is set increase.

East Renfrewshire Council has already announced that is plans a 10 per cent reduction in its roads budget over the next three years in a bid to make overall savings of £26million.

Councils are facing a financial black hole of more than half a billion pounds in only two years' time unless they make major cuts, according to an official analysis.

The Accounts Commission forecasts the gap between the amount local government spends and its income could grow from £87m in 2016/17 to an estimated £367m in the current financial year, before rising again to £553m in 2018/19.

Now the new study shows that the cost to councils is mounting as they paid £3.1 million in compensation to drivers whose vehicles were damaged by poor road surfaces in 2016. calculated that the UK's potholes have a total depth of more than 24 miles, which is almost four times deeper than the Pacific Ocean.

Scotland has the deepest and stretches to 6.364 km or 3.9 miles. motoring editor Amanda Stretton said: "Scrolling to depths of 40km (25 miles) really puts the country's pothole problem into perspective.

"They are a major bugbear among drivers, not least because of the damage they do to our vehicles - around £3.1 million worth of damage.

"The cost of motoring alone is getting more and more expensive and damage repairs is a big contributor to this, as car parts increase in price as well."

According to the industry, one in six local roads will need to be repaired or may even face closure within the next five years due to poor maintenance.

The annual Local Authority Road Maintenance (ALARM) survey, produced by the Asphalt Industry Alliance (AIA), found that 17per cent of all roads are now at serious risk of closure unless they are repaired by 2022.

Alan Mackenzie, chairman of the AIA, said: “Local authority highway teams do not have enough resources to arrest the terminal decline in the condition of our local roads and the network is not resilient enough to meet the challenges ahead."

“Potholes are a symptom of poorly maintained roads and can have a serious effect on road users but spending money fixing them in isolation, although essential, is wasteful.

"The most efficient way to deal with our crumbling roads is to fix them properly and stop potholes forming in the first place.

“It is time we had a rethink about the future funding of our roads otherwise we will end up with a network that is just not fit for purpose.”

Thousands of claims have been made by motorists about potholes throughout Scotland, but experts say not all of those who have made legitimate claims will receive compensation.

This is because of strict rules laid down by authorities which mean they must have received previous complaints about an individual pothole before they will accept responsibility.

An AA spokesman said: 'What we are seeing is money coming away from road management to plug gaps elsewhere, so essentially councils are trying to fill more potholes with less money."

According to research by Kwik Fit, 1,400 Scottish motorists a day suffered damage to their cars with a total value of £56.7million as a result of bad roads.

A Convention of Scottish Local Authorities (Cosla) spokesman said: "Scotland's Councils are committed to maintaining our local roads in as good a condition as is possible.

"This is not a simple task and roads have to compete with several other demands on council budgets."