Although they may seem redundant, buttons on pedestrian crossings are vital for disabled people to know when it is safe to cross.
Most UK crossings beep when it's safe to cross (for the blind), and have small jagged cones[1] on the bottom that can be felt spinning around in your hand (for the deaf and blind).
But don't they all beep/rotate the cone even when the button hasn't been pressed? The ones near me (in the UK) which are on a junction and operate cyclically (in conjunction with a couple of sets of traffic lights) certainly do. I've given up leaning over from my bike to push the button when I realised this!
Most UK crossings beep when it's safe to cross (for the blind), and have small jagged cones[1] on the bottom that can be felt spinning around in your hand (for the deaf and blind).
[1] http://ichef.bbci.co.uk/news/660/media/images/67872000/jpg/_...