The Access Code says:
Access rights extend to all paths and tracks except where they go over land on which access rights do not apply. Rights of way are unaffected by the legislation. Access rights apply off-path, but when you are close to houses or in fields of crops or in places where the environment is particularly vulnerable to damage, it may be sensible to follow paths and tracks where they exist. This can help to facilitate access and help safeguard the interests of land managers and the environment.
Walkers, cyclists and horse riders can all exercise access rights on paths and tracks. However, on some paths, such as those which are heavily-used or which are prone to damage, the local authority may have provided local advice on what types of use are appropriate or how different users should behave to reduce risks to safety or to minimise damage to the path surface. Following such advice can help to minimise problems.