The toads breed at Cod Beck resevoir

George McDonald of the Tees Valley Wildlife Trust told BBC Radio Cleveland it was a serious problem.

"Cod Beck is a popular picnic area and if the weather is at all reasonable it attracts a large number of vehicles.

"I have seen hundreds of dead toads there in previous years.

"There is a large toad population and they need to cross the road from their winter quarters to Cod Beck reservoir.

"That is where the problem is and this is where the rescue effort is to be concentrated.

"We simply collect the toads and place them in buckets to carry them across the road to the reservoir."

National Park Ecologist Rhona Charles said this time of year was especially dangerous for the toads.

"The toads come back every year to breed, so at this time there are thousands of toads are trying to cross the road.

Special toad crossing signs may be erected

"Once they finish breeding, they tend to leave the reservoir again.

"A couple of volunteers have carried out surveys and they reckon 40 to 50 toads a night are being killed on the roads.

"We don't know what proportion we are getting across safely, but we are hoping to increase that proportion.

"The volunteers will help the toads go towards the reservoir or away from the reservoir, whatever it is they want to do."

Ms Charles added she would like to see special road signs erected to make drivers aware of the toads.

"We are hoping to erect toad crossing signs at the side of the road... at either end of the vulnerable section, which will have a distinctive toad sign on them.

"All the volunteers will have reflective clothing and torches... but we also hope to flag down any motorists to go slowly."