I think if you're caught by a fixed camera you need your eyesight tested.
That assumes the signage is adequate or you know the road layout well. Often there is a plethora of signage and markings which is confusing or distracting, or the road markings are too worn to read especially in the dark or wet. It is easy to go through a badly signed bus gate which will get you a FPC for being in a bus lane. These are strict liability offences, that place simplicity of administration above fairness. To generate cash for Councils.