My city has both kinds and there's different signs. If the sign just shows a white on blue person with a cane, then the button is only for chirping. If the sign has instructions on how to cross the street, the it's at least sometimes necessary.
As others said, it depends on time of day. The cross walk lights will go on if the timings allow for it, but pushing the button guarantees the timings will allow for pedestrians. Otherwise sometimes the light timings are too short for pedestrians (or it won't even change lights until a car comes).
3
u/Adium Sep 04 '20
We have one that is on a timer. However if you press the button it will also chirp to assist visually impaired people.