School mornings after a storm run on a tight clock: buses at the corner, sidewalks unbroken, the lot by Nipper Maher Park still under six new inches. Osorio and Son Landscape Inc gets out ahead of it, plowing driveways and lots, hand-clearing walkways and steps, laying salt where the afternoon melt will refreeze by dark. The Lakeview streets drift and rut in a hurry, so the second pass matters as much as the first. Everyone in Waltham leaves on time and nobody gives it a thought — which is exactly the intended result. Snow work for Waltham and neighboring Watertown, Belmont and Newton.