Save your local ORPA

A right of way is a path which provides a route which can be taken by anybody, with legal protections.
In 2000 there was the CROW legislation, which added a range of other paths, with the permission of the land owner.
The Right to Roam on open access land is explained here.

There is now a period of time when rights of way need to be protected

Thousands of footpaths, alleys and bridleways across the UK face being lost forever within a decade under a clause in right-to-roam legislation, campaigners have warned.
From 1 January, walkers, horseriders – and even those taking regular shortcuts to the shops in towns – will have 10 years to apply to save any rights of way that existed before 1949 but do not appear on official maps.
Experts on land access rights say the clock is ticking to save routes that many people take for granted as public highways but that do not appear on official records.

These are known by the Ordnance Survey as 'other routes with public access’ (ORPAs).
Get involved with this by helping one of the organisations which is trying to keep the permissions intact.
To get more involved in protecting your local footpaths and right to roam, you could also consider getting involved with The Ramblers.
The Open Space Society also has more detail (PDF download)

Phil Wadey, who is involved in protecting such rights of way, says:
“These paths are all over the place. A lot of them are actually paths that are in everyday use. They are not hidden. We are not talking about paths that have fallen into disuse. There are actually people walking or riding or cycling along them. But they are not on the official map, so they will vanish if applications are not made. People won’t realise until they are gone and then it will be too late”

Image: Alan Parkinson, Footpath sign near the Roaches, CC licensed