Bridge maintenance backlog hits UK roads: 1 in 25 bridges deemed substandard

A recent study by the RAC Foundation revealed the concerning state of infrastructure on Britain's roads, with 1 in every 25 council-maintained bridges now classified as substandard.

This alarming statistic emerged from an extensive survey involving 201 out of 208 local highways authorities across England, Scotland, and Wales.

The foundation's analysis, based on responses received through Freedom of Information requests, shows that out of 73,208 road bridges, 2,928 are unable to support the largest 44-tonne lorries. This equates to 4% of the total, a slight improvement from last year's figure of 4.4% but still a significant concern for road safety and efficiency.

The term 'substandard' refers to bridges that fail to meet the criteria for carrying vehicles over obstacles such as watercourses, railways, and valleys. Councils expressed concerns over several issues impacting bridge management, notably weather and climate change effects, budgetary constraints, inflation, staffing challenges, ageing infrastructure, and coordination issues with entities like Network Rail.

Notably, the impact of weather and climate change has become a more pressing concern, with problems such as flooding, washout, and ground shrinkage due to hotter, drier conditions being highlighted.

Despite the evident need for maintenance, financial limitations mean only 292 of the substandard bridges are expected to receive the necessary repairs within the next five years. A staggering £4.1 billion is needed to clear the maintenance backlog on nearly two-thirds of the bridges managed by the councils surveyed. Extrapolating this data suggests a nationwide maintenance bill of approximately £6.8 billion.

Devon, Essex, and Somerset top the list of councils with the highest number of substandard bridges, indicating a widespread issue that spans both rural and urban areas. Similarly, councils like Hammersmith and Fulham, and Bristol show a high proportion of substandard bridges, highlighting the variability of infrastructure challenges across different regions.

The National Highways, Transport Scotland, and the Welsh Assembly provided figures for their jurisdictions, with the Welsh Assembly reporting the highest proportion of substandard bridges at 8%.

This study, conducted with the assistance of the National Bridges Group of ADEPT, underscores the urgent need for investment and strategic planning to address the growing backlog of bridge maintenance across Great Britain.

Steve Gooding, Director of the RAC Foundation, said: “As ever, we are grateful to all the authorities who answered our questions.

“This data should not be used as a stick to beat highway authorities with but seen as a weathervane which indicates the way the highway condition wind is blowing.

“While on the one hand it looks like councils are holding their own in keeping their road networks functioning, with every year which passes we are seeing the challenge of maintaining climate resilience increase in the face of more extreme weather.

“It is unrealistic to think that there will be vastly more money added to the road and bridge maintenance pot but there are measures that could help stem the tide of decline, such as a real drive to recruit, train and retain engineers with the right expertise, plus the delivery of a fresh five-year funding settlement for local roads, which would at least allow highway teams to plan ahead.

“Ideally, faced with the long-term challenge of constrained funding and deteriorating weather we desperately need innovative engineering solutions to provide cheaper, more resilient repairs.

“The real danger lies in the change in climate – more temperature extremes and more wind, rain, snow and ice put are putting an ever-greater strain on the foundations of our roads and the structures that carry them.”

Keith Harwood, chair of ADEPT National Bridges Group, said: “Our nation’s highway infrastructure represents centuries of investment, serving as the backbone of our economy and communities. However, as our bridges age and face mounting pressures from increased traffic and the impacts of climate change, maintaining their resilience becomes increasingly critical.

“The recent Grand Challenges statement from the Bridge Owners Forum underscores these issues, further emphasised by this year’s RAC Foundation report. Through insightful statistics, the report demonstrates the same themes – the financial constraints, staffing and skills shortages, and environmental factors confronting our aging infrastructure.“The ADEPT National Bridges Group extends its gratitude to the RAC Foundation for their ongoing dedication to compiling such valuable data, which highlights the evolving trends and concerns of Bridge Managers nationwide.”