Why do non-pedestrian controlled crossings need the button pushed?

Question

There are plenty of intersections where a walk signal comes on automatically, why do some intersections require a button push to initiate the walk signal when it doesn’t seem to make a difference in light timing or duration?

In: Engineering

Answer 1

It might behave differently depending on time of day. A lot of signals change to on demand only at night. Also without button the traffic may stop normally but the crossing signal may be short or non existent.