Almost half of Slough's road bridges are not strong enough to carry heavy lorries a new study has revealed.

The study into the state of Britain's road bridges was carried out by the research charity RAC Foundation, which put Slough at the top of the list of individual borough councils with a percentage of bridges that could not safely take lorries weighing 44 tons. In practise this would represent a cut off point at the lower weight of 40 tons.

The study reveals that 17 out of Slough's 36 road bridges cannot safely take heavy lorries.

Data analyst Bhavin Makwana said that the findings related to road bridges over a one and half metre span carrying traffic.

He did it did not necessarily mean bridges were dangerous - just not suitable for larger vehicles.

He said: "To put it in context we asked each council whether - if they had unlimited resources at their disposal - they would want to bring all their bridges up to standard.

"Slough said they would like to."

A council spokesman for Slough said this week that the authority had been proactive in managing its bridges - investing £1million towards the Stoke Poges Lane bridge.

It had joined with five other Berkshire authorities in securing £17million from the Department of Transport's local highways maintenance fund, matching the amount from its own budget.

But the spokesman said that roads serving local areas did seem to come off worse than larger road, with the Government planning to invest more than £1.1million a mile on national roads for the rest of the decade - and only £27,000 a mile on local roads even through they accounted for 97 per cent of the country's total.

The statement answered concerns about lorry drivers ignoring bans on using some bridges because of bad Sat Nav instructions, saying: "Not all of the bridges in Slough are suitable for heavy lorries, and as well as having alternative routes for this type of traffic the council’s highways team have implemented regular monitoring of local bridges to alert the borough to any potential action required.”