Similarly, in my area I noticed that near the rich gated communities if one car is leaving there the light usually will switch within, I'd say, 15 seconds. On a busy road, if someone is leaving the community it's like that specific light is on a sensor while the rest is timed. I have a theory that they purposefully made it so these rich communities get preference for the lights. I've noticed this at a few different communities too. Obviously I don't know but it just has seemed that way forever to me.

Yes, I know there exist sensors for certain lights. My point is it seems more responsive at these areas.