Dongducheon - Incheon) GI: Gyeongin Express (Yongsan – Dongincheon) GI LE: Gyeongin Limited Express (Yongsan – Dongincheon) GB A: Gyeongbu Express (Cheongnyangni – Cheonan or Sinchang(Soonchunhyang Univ.)) GB B: Gyeongbu Express (Seoul – Cheonan or Sinchang(Soonchunhyang Univ.)) ※ Only Korail trains are used for express trains. Key: Yeongdeungpo – Gwangmyeong shuttle service Byeongjeom Depot spur service Historical Timeline 1974 August 15: Line 1 is officially opened with 9 stations from Seoul to Cheongnyangni (whose distance is ), creating a system of 28 stations (excluding the 9 metro stations) on national railroads from Seongbuk station (now: Kwangwoon University station, the then-northern terminus) to Incheon Station and Suwon Station. Korail is named Korean National Railroad, with Line 1 just referring to the Seoul-Cheongnyangni section. 1978 December 9: The Gyeongwon Line from Yongsan to Seongbuk opens as a new branch, with Ichon and Seongsu (now part of the Jungang Line). 1979 February 1: Yuljeon Station is opened. 1980 January 5: Sinimun Station is opened. April 1: Seobinggo, Hannam and Hoegi (now part of the Jungang Line) are opened. July 10: Seongsu is renamed Eungbong Station 1982 August 2: Seoksu Station is opened. 1984 January 1: Yuljeon Station is renamed Seongdae-ap Station. May 22: Sindorim Station is opened. November 20: Baegun Station is opened. 1985 January 14: Seokgye Station is opened. April 20: Chang-dong is opened as a northward extension. August 22: Wolgye and Nokcheon are opened. October 18: Oksu Station (now part of the Jungang Line) is opened. 1986 September 2: 6 stations from Uijeongbu to Chang-dong are opened as a northward extension. 1987 October 5: Uijeongbu Bukbu Station is opened. December 31: Jung-dong Station is opened. 1988 January 16: Onsu Station is opened. October 25: The Ansan Line is opened as a southward branch, from Geumjeong Station to Ansan Station. 1994 July 11: Ganseok and Dowon are opened. December 1: Seongdae-ap Station is renamed to Sungkyunkwan University. 1995 February 16: Guil Station is opened. 1996 January 1: Hwigyeong Station is renamed to Hankuk University of Foreign Studies Station March 28: Bugae Station is opened. 1997 April 30: Sosa Station is opened. 1998 January 7: Singil and Doksan are opened. 2000 Korea National Railroad and Line 1 are integrated as Seoul (Metropolitan) Subway Line 1. 2001 November 30: Dohwa Station is opened. 2003 April 30: Seryu and Byeongjeom are opened as a southward extension. The Ansan Line service is replaced with an extended