In Kentucky, I've encountered crosswalk buttons that don't actually change the traffic-light cycle at all, but the walk light doesn't come on during parallel gr

In Kentucky, I've encountered crosswalk buttons that don't actually change the traffic-light cycle at all, but the walk light doesn't come on during parallel green-light traffic unless the button was pushed. I have no idea what that's supposed to accomplish, unless it's just another level of placebo.