NEW YORK — A quick-thinking commuter saved a teenager who fell on the subway tracks by pushing him down into a furrow between the rails, allowing an approaching train to pass right over them, police said. An 18-year-old man had some kind of medical problem Tuesday and fell onto the tracks, which are a few feet below platform level, police said. Wesley Autrey saw him fall, jumped down onto the tracks after him and rolled with him into the rut between the rails as a southbound train was coming in.- snip-