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 it will cost £2.25 billion to bring Scotland's roads up to scratch and with councils continuing to tighten their belts, that repair bill may rise further.

East Renfrewshire Council has already announced plans to cut its road budget by 10 per cent over the next three years to reduce costs £26 million.

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 analysis by the Accounts Commission.

UK motorists received £3.1m in compensation from vehicle damage linked to poor road surfaces in 2016.

Steve Gooding, director of the RAC Foundation, said motorcyclists are particularly at risk from the failure to combat potholes.

“From the mere blemish on the road surface to the fully formed crater few Scottish drivers will be far from a pothole," he said.

"They not only cause damage to vehicles but risk the life and limb of those on two wheels.

"Investment in new infrastructure is always welcome but motorists routinely regard looking after what we already have as the number one priority.”

It has been 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.

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

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."

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

A spokesman for motoring association AA 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 maintaining the roads was "not a simple task" and had to compete with "several other demands on council budgets".

A Scottish Government spokesman said: “The local road network is the responsibility of local authorities and it is their responsibility to allocate resources, including on the maintenance of local roads, on the basis of local needs and priorities.

“Transport Scotland maintains the trunk roads and the most recent Audit Scotland report on roads maintenance found that eighty per cent of the network was in an acceptable condition. The maintenance budget for trunk roads increased to over £199 million in 2017/2018,