Bats reject 'safe way' bridges over Norfolk - Suffolk dual carriageway

A number of bat species live in the forests of Breckland

Special bridges costing £350,000 to help bats cross a dual carriageway on the A11 are a "waste of money", according to the author of a new study.

They were built at six crossing points on the new nine-mile road between Barton Mills in Suffolk and Thetford in Norfolk - but bats are shunning them.

The wire mesh and net bridges were designed to echo bat radar and guide them across the road in safety.

Highways England said the specially-designed bridges had been modified.

The organisation said it was obliged to protect existing endangered species and always carried out environmental studies on new projects.

"The wire bat bridges are only used when other options have been discounted and their designs have been modified to improve their potential," a statement said.

Swathe across forest

However, the few bats now crossing at these points are flying dangerously low, a study by Leeds University expert Professor John Altringham showed.

Six wire mesh and netting bridges hung above the A11 at identified bat crossing points are rarely used

He said he had studied the design at many projects and said it was a waste of public money.

He would have preferred a so-called "green" alternative using existing vegetation stretched on wires across the road.

"There may have been lots of bats crossing at these point in the past, but not now. Those that do cross fly too close to the ground," he said.

Local bat expert John Goldsmith said there were about 12 different species in nearby Thetford Forest.

"When the road was a single carriageway some of the tree tops touched on parts of the road and bats used these points to navigate," he said.

"The new road cuts a wide swathe through the forest and these bridges were designed to keep bats above the level of traffic."

The dual carriageway cuts a swathe through Thetford Forest, where 12 species of bat make their home