Geograph - photograph every grid square

This minor road lies above the River South Tyne and below Kirkside Wood. On OS mapping it's marked in yellow ink which presumably means that it's a public road and that one can walk it and motor over it. And yet here the main part of the carriageway has a cattle grid across it (of itself nothing unusual) with signage telling that the grid is private!
Of course there's no suggestion that the public should avoid using it. It's assumed that the grid has been privately installed (but surely with appropriate consent) and that the 'owner' is seeking to avoid responsibility should any mishap occur in making a crossing.
A curious situation, all the same!