Cumbria has one of the highest numbers of substandard bridges in the country, it has been revealed today.

A study by the RAC Foundation has found that more than 3,200 council-maintained road bridges across Britain are substandard and not fit to support the heaviest lorries which can way up to 44 tonnes.

Cumbria is one of 10 councils in Britain with the highest number of such bridges.

There are 71 bridges in Cumbria failing to meet the standard which is less than a third reported for Devon, the highest ranked council with 249 substandard structures.

Many of these structures have weight restrictions and others are under programmes of increased monitoring or managed decline.

The number of substandard bridges has increased by 35 per cent over the past two years, the analysis revealed.

They represent around 4.4 per cent of the 72,000 bridges on the local road network.

Some of these bridges are substandard because they were built to earlier design standards, while others have deteriorated through age and use.

RAC Foundation director Steve Gooding said: "It's the pothole backlog that normally hits the headlines but it is easy to forget all the other aspects of road maintenance that councils are involved in; from clearing ditches to cutting verges to maintaining bridges.

"In the face of growing traffic volumes and ageing infrastructure the danger is that without an adequate long-term funding settlement we will see more rather than fewer bridges with weight restrictions, with the backlog bill getting bigger all the time."

There has been a spate of lorries causing problems on bridges where they exceed the weight limit.

If funds were available then councils would want to bring 2,110 of the bridges back up to standard, but budget restrictions mean only 416 are expected to be restored within the next five years, according to the report.

The cost of clearing the backlog of work on all bridges is estimated to be £3.9 billion, but councils are currently spending just an eighth of that per year maintaining their bridge stock.

A total of 199 councils provided data for the research.

The survey was carried out in partnership with the national bridges group of voluntary organisation the Association of Directors of Environment, Economy, Planning and Transport.

Martin Tett, transport spokesman at the Local Government Association, representing more than 370 councils in England and Wales, said the report "underlines the chronic need for more investment in local roads".

A Department for Transport spokeswoman said: "Local highway authorities are entirely responsible for maintaining their bridges. We have provided a record £6.1 billion up until 2021 for roads maintenance outside London, which councils can prioritise to help repair and strengthen bridges."