The recent wet weather storms and risk of freezing conditions towards the end of the month, threaten to deliver the worst pothole season ever seen in the UK, according to Warranty Direct’s road campaign website, Potholes.co.uk.

Potholes traditionally appear on Britain’s underinvested road network in greater numbers between January and April. In 2013, Warranty Direct, which insures motorists against mechanical damage, estimated that pothole related repair bills cost almost £730million – a 159% rise in three years.

The Met Office reported that parts of southern England experienced around twice the average amount of rainfall normally expected in December.

With local authorities calculating a road network pitted with 200,000 potholes needing repair, persistently heavy rain and flood water has now created the perfect storm for a new plague of potholes.

“The worst is yet to come,” says Rory Buckley of Warranty Direct’s potholes.co.uk. “This wet weather will be saturating roads right across the UK with existing potholes channelling water to weaken the road’s substructure, literally paving the way for even more potholes and defects to arise.”

Current conditions are also treacherous for drivers with the growing threat of ‘invisible potholes’ – filled with rainwater and much harder to spot, particularly in the dark winter commuting hours. 

Analysis of over 150,000 Warranty Direct policies between 2010 and 2013 found that, on average, 6.6% percent of cars suffered axle or suspension damage linked to potholes or road defects.

However, in 2010 axle or suspension damage made up just 4% of all claims, in 2013 this had increased to 10.1% – a 159% rise in cases.

With around 29.4million cars on UK roads in 2013 and an average repair bill of £247, the total annual cost for the estimated 2.9million cars struck by axle and suspension damage was calculated to be £729,396,000. The figure excludes commercial vehicles.

Heavy rainfall undermines the lower, structural layers of the road creating cracks, fissures and more potholes – which are then enlarged by a daily procession of vehicles widening and deepening the craters.

Buckley adds: “Potholes and other road defects can cause sudden jarring or regular jarring which accelerates wear and tear to axle and suspension components, often leading to failure. Damage to wheel rims and punctured tyres are also a common fault of potholes.”

While the average repair bill for pothole-induced axle or suspension damage is £247, Warranty Direct and Potholes.co.uk have identified recent claims as high as £2,700. The average cost for a council to repair a single pothole is only around £50.

However, with almost 2million potholes filled over the last year at a cost of £99million, the shortfall in annual road structural budget is calculated to be £741million – £6.2million on average per authority.