A £63,000 bridge to help dormice cross a busy bypass safely has not been replaced 16 months after it fell down.
The crossing was one of three built over the Church Village bypass near Pontypridd in 2010 - at the cost of £190,000 to the taxpayer.
Rhondda Cynon Taf council has been criticised for not replacing one of the bridges, which collapsed in storms in January 2016.
The council said a proposal was being considered by Natural Resources Wales.
Made of wire mesh tubes suspended between trees and tall poles, the crossings were put in place as part of wildlife protection plans ordered before the bypass was approved.
The Wildlife Trust of South and West Wales said, while the effectiveness of the bridges was not yet clear, families of dormice could become "extinct" in the event of disease if they were unable to move habitat due to the road.
Rose Revera, people and wildlife officer, said: "Dormice are easily predated upon, they tend to travel in the tops of trees. If a road goes through a wood or shrub land it causes a huge barrier they cannot cross.
"If they are not able to move they are more vulnerable".
The Taxpayers' Alliance said the situation was "completely absurd" as the bridges had been paid for by the Welsh Government as part of the construction of the £4.4m road.
John O'Connell, chief executive of the group, said paying £190,000 in the first place for crossings for mice was wrong.
He said: "When the council should have been looking to cut out waste and find savings, local taxpayers have every right to question how this was ever signed off.
"Their intentions might have been good but £190,000 is a huge sum of money and surely the council could have found far-cheaper ways of doing the same thing."
The bypass opened more than 20 years after the need between Church Village, Llantwit Fardre and Tonteg was first identified to ease congestion on the A473.
A council spokeswoman said: "Rhondda Cynon Taf council engineers and ecological specialists have formed a proposal which is currently being considered by NRW."