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.
Stations between Harrow-on-the-Hill and Uxbridge (except Ruislip) were open gradually to stimulate development around the area (1900s - 1910s)
London Midland and Scottish Railway quadrupled the tracks between Barking and Upminster which enabled several stations to be built on the local line (1930s)
^Freemark, Yonah (2008-09-08). "With Infill Stations, Older Transit Agencies Extend Their Reach". Destination:Freedom. Archived from the original on 2014-09-11. Retrieved 2008-09-09. 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.
^"2019年春ダイヤ改正(3月16日【土曜日】)" [Timetable Revisions for Spring 2019 (March 16 【Saturday】)] (PDF). West Japan Railway Company. 2018-12-14. Retrieved 2018-12-14.