Green Man is what you see when it is safe to cross.  We got a kick out of it because it made us think of Charlie Day in Always Sunny in Philadelphia!  If you aren't safe to cross, the man is, of course, red.  Also noticed that in Northern Ireland, when cars are stopped at a red light for a cross walk, the light turns to yellow to let the drivers know it is about to turn green.  Not sure it's a good idea, as cabs tend to start going forward on the yellow!  The take away on this is Be Careful when walking in crosswalks in Belfast!