They're pretty common elsewhere, but many intersections have fixed cycles before they actually pay attention to the sensors - they're only polled when another c

They're pretty common elsewhere, but many intersections have fixed cycles before they actually pay attention to the sensors - they're only polled when another cross-traffic cycle is about to come up. But this is about the situation in which the main road should be flashing yellow at low-traffic times, and the cross streets flashing red. Or, all flashing red if it's a limited-visibilty intersection. There's one of the latter near me, and it really only needs full cycles during morning and evening rush. The rest of the time, it would be faster for all involved as a four-way stop.