marinyork said:
Sustrans. Councils revamp sections very occasionally.
A seriously complex answer really.
The
responsibility for cleaning, safety and maintenance depends on who has ownership of it.
Sustrans, the local council and its various officers, a number of road and highway agencies, the canal and waterways authorities and sometimes the Railways or even local landowners. It really depend on who owns the land which that stretch of the NCN is on.
Finding out who does actually have the ownership and responsibility for maintenance for a particular stretch is tricky.
Sustrans local volunteer rangers and Sustrans staff will try and co-ordinate and encourage the various people to do the major work. Smaller stuff tends to fall to the volunteers in my area.
It kind of means that if it needs a bit of brush cutting and litter picking, volunteers do it but if its a fallen tree then someone else does.
A lot depends on local circumstances.