They are also used here in Durban South Africa. Sadly they are not exactly the most vandal proof item around, as many of the hundreds installed no longer work, and as the traffic signal maintenance is not exactly done by the brightest, many are faulty, never repaired and non functional. The intelligence is in a die cast box typically mounted higher up the pole, and then led down inside via a few cable cores to the signal, and they are powered by the traffic controller, I would guess using the 230VAC used to drive the pedestrian crossing lamps, as typically there are no spare wires in the cable bundles used to interface between the controller and the pedestrian push buttons.