Twelve Corners before sunrise in January: traffic lights swinging, salt haze in the headlights, a plow blade sparking once on a seam of pavement. Brighton Mower Service is out in that hour, clearing driveways and lots, cutting walkways down to the concrete, spreading salt so the day's melt does not refreeze into a rink by dusk. Rochester winters never come all at once; they come in shifts, so the trucks come in shifts too. By the time the school buses roll, the pavement is dark and dry and nobody gives it a thought — which is exactly the point.