The first real snow of December tends to find the middle of town first — flakes turning slowly under the lights on West Main Street, an inch down before anyone thinks to move a car. Doug Curtiss Landscape Contractors, Inc runs Westborough driveways and lots from that night through the last gray storm of March. Plowing opens the drive, shoveling opens the steps and the path to the door, and salt goes down where an afternoon melt becomes early-evening black ice. Storms here rarely arrive at a convenient hour, so the schedule bends to the weather instead of the other way around. Clear pavement by morning is the whole of the promise.