Information gathered by the RAC Foundation from almost 200 councils indicates that numbers of inspections for damage caused by river flow to susceptible bridges are currently in decline. Almost 4000 ‘stage 1’ scour assessments were conducted on bridges in 2018-19 compared to just under 2700 last year.

“The serious flooding we have just experienced across England means bridges with foundations in watercourses will have again been subjected to scouring,” said chair of the Association of Directors of Environment, Economy, Planning & Transport’s national bridges group Kevin Dentith. “Bridge owners should satisfy themselves that appropriate action is in place to ensure the more susceptible bridges are protected.”

He added: “It is worrying that whilst the industry knows scour is the main cause of bridge collapse the survey shows the number of scour assessments has dropped so significantly where it should be increasing. This trend needs to be reversed.”

RAC Foundation director Steve Gooding also described the downward trend in scour assessments as “worrying” and said: “This is storing up trouble for the future as our weather gets more extreme and traffic volumes rise again after the Covid-19 restrictions.”

Across the local authorities surveyed, 3105 bridges over 1.5m in span were identified as being ‘substandard’, meaning they are unable to carry the heaviest vehicles permitted on British roads. This marks a rise of 1.6% on the figure 12 months before.

This means 4.3% of the total council managed bridge stock is now considered substandard, with many of these structures subject to weight restrictions or under programmes of increased monitoring.

Between them, councils say they ideally want to bring 2256 – or 73% – of the substandard bridges back up to full carrying capacity. However, budget restrictions mean only 392 are expected to undergo the necessary maintenance work within the next five years.

Commenting on the findings, Local Government Association transport spokesman David Renard said: “Bridges are a vital part of our highways infrastructure that connect communities and business. Councils are doing their best to ensure they are well maintained and withstand extreme weather.

“However, this is becoming increasingly challenging in the face of a backlog of nearly £10Bn to bring our roads up to scratch.”

The research also found that Devon is the county with the highest number of substandard bridges in Britain, at 233. This represents 9% of its bridge stock.

Almost 40% of Liverpool’s 38 bridges are substandard, while Hammersmith & Fulham, Kingston upon Thames, Brent, Southend on Sea, Barking & Dagenham and Southampton all have above 25% of their bridges in a substandard condition.

(Photograph: Philip Gomm)