An infill station (sometimes in-fill station) is a train station built on an existing passenger rail, rapid transit, or light rail line to address demand in a location between existing stations. Such stations take advantage of existing train service and encourage new riders by providing a more convenient location. Many older transit systems have widely spaced stations and can benefit from infill stations.[1] In some cases, new infill stations are built at sites where a station had once existed many years ago, for example the Cermak–McCormick Place station on the Chicago 'L''s Green Line.
The advantages of infill stations result from the fact that people are simply more likely to use transit when they're closer to it — and from the fact that the older transit systems in many cities have widely spaced stations that are under-serving potentially significant markets.