Secondly, amber have the same meaning as red, the only problem is that everything think they mean "oh go on, three more cars through before we go red".
^ As you've just quoted yourself, Ed, the meaning isn't quite the same, as it also includes the additional caveats you've included in the quote. Red is 'stop, no ifs or buts'. Amber is 'stop, except when ...'.
Secondly, amber have the same meaning as red, the only problem is that everything think they mean "oh go on, three more cars through before we go red".