Four in the morning on the Cambridge Turnpike, and there is nothing moving but plow lights and blowing snow across the lane markers. Steve's Lawn Care is out in it, clearing Lincoln driveways and walkways so the first commuters of the day have somewhere to point the car. The blade takes the long runs; the shovel handles the steps, the mailbox side and the strip in front of the garage door where the pile always wants to sit. Salt goes down last, on the walk and the slope, where the refreeze would otherwise catch someone at dusk. Then the sky lightens over bare pavement, and that is a good end to a long night.