What causes potholes and why does the UK have so many?

As shock figures reveal the length of time some UK councils took to fix potholes, an explanation on their cause and why Britain seems to have so many.

South Bucks, UK. 11th April, 2023. A vehicle passes large potholes in a road. The Asphalt Industry Alliance recently reported that 18% of the local roads network is considered to be in poor condition with less than five years of life remaining. Holes in roads can damage vehicles and endanger all types of road users. Credit: Mark Kerrison/Alamy Live News
A vehicle passes large potholes in a road in South Buckinghamshire. (Alamy)

Some councils in England are taking as long as 18 months to repair potholes, data has revealed.

Figures obtained from councils across the country by the Liberal Democrats showed there is a "postcode lottery" when it comes to fixing potholes.

Repairs of potholes took up to 567 days in Stoke-on-Trent and up to 556 days in the Westminster City Council area, according to figures obtained by the party through freedom of information (FOI) requests.

Last month, prime minister Rishi Sunak promised to clamp down on the UK's potholes, pledging £200m to tackle the problem in the recent budget.

Read more: Pothole repair budgets reach 'record high' in England and Wales

Prime Minister Rishi Sunak with Darlington Council leader Jonathan Dulston (far left), Tees Valley Mayor Ben Houchen (far right) and Darlington MP Peter Gibson (second from left) in Firth Moor looking at a pothole during a visit to Darlington, County Durham, as potholes take more than 18 months to be fixed in some areas, the Liberal Democrats claimed as the party blamed a
Prime minister Rishi Sunak, second from right, inspects a pothole in Firth Moor, Darlington, Durham. (PA)

According to the Lib Dems' figures, 556,658 potholes were reported in the financial year 2021/22 across 81 councils, up from 519,968 in 2017/18.

Roads in Derbyshire County Council were the hardest hit with 90,596 potholes, followed by Lancashire County Council with 67,439 and Northumberland County Council with 51,703, the party said.

Watch: Councils filling potholes every 19 seconds'

It said the government had created a “pothole postcode lottery” by cutting local authorities’ highways maintenance budgets by £500m since 2020-21 and announcing only a £200m top-up to the national potholes fund in the budget.

What is a pothole and how do they form?

A pothole is a depression in a road surface caused by wear or sinking.

They start out as tiny cracks in the surface but can grow if not fixed.

LONDON, ENGLAND - JUNE 10:A pothole filled with water in a road on June 10,2022 in London, England. (Photo by Peter Dazeley/Getty Images)
A pothole filled with water in a road in London in June 2022. (Getty Images)

The friction of vehicles' tyres on a road heats up the surface and causes it to expand.

Over a period of time, this expansion leads to cracks in the surface. Water can then seep into these cracks. Potholes are formed when the water in those cracks freezes and thaws.

Why does the UK have so many potholes?

The UK is more susceptible to potholes because of its climate.

Cold and wet weather, particularly during the winter months, means water can get into those cracks in the road and then freeze, eventually leading to potholes.

The heavy road use and traffic on the UK's roads is also a factor.

Councils also have tight budgets to fix potholes.

How to report potholes?

Anyone who wishes to report a pothole can go to the government's dedicated website for the problem.

From there, they will be directed to their local council's pothole reporting service, where they can fill in an online form.

To report the pothole, they need the location of the pothole and details of its size. They must also upload any pictures of the pothole.

File photo dated 11/05/18 of a car hitting a pothole on a road, as drivers called the AA to almost 1,900 pothole-related incidents every day last month, the breakdown service has said.
The government has vowed to clamp down on the UK's potholes. (PA)

Councils vow to inspect the area identified within about three to five working days.

If the pothole is on a motorway or an A road then reports should be directed to Highways England.

In Wales, roads are managed by Traffic Wales, while potholes in Scotland can be reported at My Gov Scotland.

In Northern Ireland, potholes can be reported through the NI Direct website.

How to claim for pothole damage?

The government says motorists may be able to claim compensation if their vehicle is damaged by a road.

They should contact the organisation responsible to tell them about the damage, why they think they are responsible and details of where and when the damage was caused.

According to the AA, motorists should start by reporting the pothole to their local authority.

After having their car repaired, they may be able to claim compensation from the council.

Motorists should inform the council of the location of the pothole and include details of quotes, invoices and receipts for their repairs.

If the claim is rejected, motorists can appeal.

Watch: Rod Stewart hits the road to fix Essex's potholes