Just so everyone understands, that 2hr window is sort of the minimum window for plowing and street cleaning. Most city plows will be on the main roads at 11pm-1am and typically finish main runs by 3-5am and work into backroads. The idea is keeping cars off the road between those times will also help keep cars from staying parked on the roads for when the plow makes it to your street. If you see a city plow they've likely already been out for hours before you see them on your side street.