Main Street through the North End is awake before daylight in winter — buses, bodegas, shovels scraping in front of every storefront. Mendez Tree Service LLC plows and clears through those blocks and the tight side streets of Brightwood, where parked cars leave a plow about one lane to work with. Salt and sand go down on the walks and the ramps, and the banks get pushed back to keep the corners open to sightlines. Storms blow down the valley here and the river holds the cold long after the sky clears. Getting a doorway and a driveway open by first light is the whole ambition, and it is a good one.