There are busy intersections where the buttons are installed, but are only active outside of rush hours or on weekends or not on weekends or only when the circus is in town etc.
Because the programming of the lights is different to facilitate maximum throughput (f.e. with a green wave) in some periods, and the walk signs are on a constant/different timing then.
Because the programming of the lights is different to facilitate maximum throughput (f.e. with a green wave) in some periods, and the walk signs are on a constant/different timing then.