by Martin Jefferies

Drivers in Kent are bracing themselves for a bumpy ride, as potholes on some of the county's busiest roads will soon be even bigger before they are filled in.

From 2015, potholes on roads operated by the Highways Agency will need to be at least 15cm wide or 4cm deep before repairs are classed as urgent.

In Kent, these roads include the M2, the M20 the A2 and part of the A249.

Previously, contractors had to provide a "safe, even and comfortable road surface for all road users".

The decision was described as "worrying" by the Institute of Advanced Motorists (IAM), which fears drivers' safety could be jeopardised.

Simon Elstow, head of training for the IAM's 'Drive and Survive' programme, said: "At night and during heavy rain, it can be difficult to distinguish between a pothole and a puddle but if you suspect it's a pothole, you're likely to take evasive action or adopt a different driving style, and that could bring you into conflict with other road users."

Mr Elstow added that the cost of repairs to vehicles hitting potholes, such as having a car's tracking realigned, are already "astronomical".

But a spokesman for the Highways Agency, which is reponsible for maintaining motorways and major trunk roads in England, said the changes - which will come into effect in the South West later this year - would reduce the cost to the taxpayer of repairing potholes by around a fifth.

He insisted: "We will continue to maintain our roads to the highest safety standards."