in the usa, i've definitely seen lights where a larger road crossed a smaller one, and the small road green light stayed green longer if someone had pressed the

in the usa, i've definitely seen lights where a larger road crossed a smaller one, and the small road green light stayed green longer if someone had pressed the pedestrian crossing button. which does seem like a sensible use of the button - from a flow-control point of view you want the large road green a lot more of the time than you want the small one green, but if someone is walking across they're going to be potentially a lot slower than the traffic (people with walkers, e.g.)