The condition of roads in England and Wales has continued to decline despite councils spending £144m filling in two million potholes this financial year.
An annual survey carried out by the Asphalt Industry Alliance (AIA) found less than half (47%) of all local roads are reported to be in good structural condition.
The AIA estimated that the remaining 53% have less than 15 years' structural life left if measures are not taken to ensure they are well maintained.
It calculated that £16.3bn is needed to tackle the backlog of carriageway repairs and bring the network up to a standard where it can be efficiently maintained.
AIA chair Rick Green said: 'Local authorities have a bit more money to spend this year but the impact of rising costs due to inflation means they have actually been able to do less with it.'
