alt Hacker NewsThey effectively don’t do anything in most elevators in the US during normal operation. The ADA requires elevator doors remain open at least 3-seconds. Usually, people-moving elevators are most efficient when doors close as quickly as possible, so they start closing exactly at 3 seconds. I’ve used elevators with less common use cases — huge ones in hospitals, freight elevators, hotel service elevators — that might be configured to stay open longer than the 3 second minimum, assuming people will push the door close button as soon as they’re ready.
Nothing you've said indicates why the button does nothing.
I can enter an elevator is under a second and push the button. This is doubly faster when not waiting for the doors to open fully, effectively making my button push at 0 seconds from door full open.
If you're saying "3 seconds is not long to wait, so it's the same as the button doing nothing", this is false, untrue, and I often use it.
Alternatively, requiring elevator door to wait 3 seconds as a default does not negate someone overriding that.
I've manipulated the button and seen timing differences. It does work. It does make a difference.
Did you mean something else?