Klunk, I just noticed on the horse thread about your RoW’s being closed for old mine workings. It’s very rare for a RoW to be extinguished, but depending on how much work there is to cap / infill them it could take some time.
It could also take some time to find out who has to do the work as the legislation regarding old mines is pretty complicated (leases / mineral rights / landownership / etc). 6 month closures are the longest you can get, but they could put another one on when it expires.
It would definitely be worth asking your PRoW department if they are going to provide a better alternative route, or even a permissive path / diversion to the existing RoW.