As always, see
here for the official documents now in full force.
In summary, provided the land concerned is public, and not residential i.e. somone's garden around their house, then the landowner cannot restrict access by erecting a sign along the 'Private, No Access' lines. In fact, they can be reported for attempting to restrict access if they do.
Crossing public land for access, even if only a small piece, is precisely what the Code is intended to clarify by conferring rights and duties on both walker and landowner.