Volunteers cleaned up trolley tracks on the Astoria riverfront Saturday morning, work they must do every winter to prepare the tracks for spring and summer. A portion of the tracks is closed downtown for waterfront bridge replacement work. The work is expected to keep a major portion of the Astoria Riverfront Trolley’s usual route closed or inaccessible through late May. But volunteers plan to run the trolley later this month on a shorter route for spring break. The route schedule is still being finalized.