I think what most people would assume 'private' to mean in this sort of case (i.e. not a supermarket etc.) is not the same as what the Road Traffic Act considers private (i.e. not accessible to the public).
Something like an office's car park may say 'private land' or similar but i'm fairly sure that if you can just drive into it, it doesn't count as a 'private car park' as far as the RTA is concerned.
Something like an office's car park may say 'private land' or similar but i'm fairly sure that if you can just drive into it, it doesn't count as a 'private car park' as far as the RTA is concerned.