Grymes Hill is a problem worth solving: driveways pitched like ramps, curves that hold ice long after the flats have let go. Alliance Landscaping and Masonry takes the hill and its neighbors in winter, plowing the steep approaches, shoveling the walks and the stairs cut into the slope, salting the shaded corner that always refreezes. A hill driveway brought back to bare pavement is a small piece of engineering, and it is meant to hold. From up there you can watch the harbor go gray with weather a good hour before it arrives, which is exactly the head start you want. The trucks are rolling by the time it reaches the crest.