It will take at least eight years to repair the outstanding backlog of potholes in the West Midlands – and that is if the region’s roads don’t get any worse.

The repair bill to clear the mountain of essential maintenance is currently estimated to be almost £41.5 million for each local authority in the area, a report by the Asphalt Industry Alliance (AIA) revealed.

The study claimed that on average each authority in the West Midlands filled in more than 14,800 potholes during 2012, but fielded an average of almost 10,000 complaints from motorists.

However, the figures could be even worse because several West Midland councils, including Walsall and Solihull, failed to respond to the survey.

Local authorities are responsible for 95 per cent of the country’s roads. The AIA said 20 per cent were reported as being in “poor condition,” which is defined as having five years or less life remaining before needing to be replaced.

It called for a government cash injection to help authorities handle the backlog of repairs.

AIA chairman Alan Mackenzie said: “Constantly having to patch up crumbling roads rather than using highway engineers’ skills properly, to ensure good road condition in a planned and cost-effective way, is nonsensical and costly.

"It’s time to stop the rot. The Government needs to make sufficient funding available now that will enable local authorities to get their roads back into a condition that will quickly and directly boost the economy, help businesses and improve local communities.”

Edmund King, president of the AA, agreed with the findings. He said: “Ring-fenced finance must be found to plug an increasing gap in highway budgets – otherwise drivers and local authorities will end up paying more to repair damage that could have been prevented.

“Things look particularly bleak, with more potholes, a bigger maintenance backlog and less cash.

“We urge drivers to report potholes to highways authorities to allow them to take action and prevent road users from being endangered and their vehicles suffering damage.”

Birmingham’s repairs are undertaken as part of a 25-year £2.7 billion deal with construction giant Amey.

It said it had been working with the city council for several years to identify and clear any outstanding repairs to the city’s 2,000-mile road network.

In Dudley, council chiefs have pledged almost £750,000 to carry out the repairs in 2013. The council had originally put aside £549,400 to target potholes after council taxpayers had called for the extra cash.