Editing Seoul Subway Line 2 (section)

== History ==
{{More citations needed section|date=July 2024}}[[File:Subway sign Seoul Metro.jpg|thumb|Former [[split-flap display]] passenger information system signs used on Seoul Subway Line 2 from 1980 until replaced with flat-screen TV displays in 2005–10.]]
[[File:지하철 2호선 2단계 개통 기념 지하철표.jpg|thumb|Commemorative ticket issued for the opening of the second phase of Seoul Subway Line 2 on December 23, 1982.]]
[[File:Early 1980s Seoul Subway Map - Flickr - skinnylawyer.jpg|thumb|Fragment of an early-1980s Seoul Subway map, showing the western two-thirds of the Line 2 loop as a green line.]]
In 1972, then-[[Mayor of Seoul]] {{ill|구자춘|lt=Koo Ja-choon|ko}} (1932–1996) changed the existing plans for the Seoul Subway to better enable connectivity around the growing Seoul City and allow for development to take place across the [[Seoul Metropolitan Area]]. Line 2 was built in 1978–84 together with the Seongsu Branch (the second Sinjeong Branch was built 1989–95). Dangsan bridge was closed for reconstruction in 1996 and reopened November 22, 1999. The old steel girder bridge was replaced by a {{convert|1.3|km|adj=on}} long concrete bridge between [[Dangsan station|Dangsan]] on the southern side of the river and [[Hapjeong station|Hapjeong]] on the northern bank.

[[Yongdu station]] on the Seongsu Branch (between Sindap and Sinseol stations) is the first station in the Seoul Subway system with operating [[platform screen doors]]. As of 2008 platform screen doors are operating at all stations along Line 2. New [[rolling stock]] has also progressively came on line, replacing older vehicles.

*October 31, 1980: Sinseol-dong – Sports Complex (via Seongsu) section opened
*December 23, 1982: Sports Complex – Seoul Nat'l Univ. of Education section opened
*September 16, 1983: Euljiro 1-ga – Seongsu section opened; Sinseol-dong – Seongsu section separated as '''Seongsu Branch'''
*December 17, 1983: Seoul Nat'l Univ. of Education – Seoul Nat'l University section opened
*May 22, 1984: Seoul Nat'l University – Euljiro 1-ga (via Sindorim) section opened; the '''Circle Line''' (the longest in the world at {{Convert|54.2|km|mi|abbr=on}} until it was surpassed in 2013) is completed.<ref name=":0">{{Cite web |title=개요 및 연혁 |trans-title=Overview and History |url=http://www.seoulmetro.co.kr/kr/page.do?menuIdx=512 |url-status=live |archive-url=https://web.archive.org/web/20240205120552/http://www.seoulmetro.co.kr/kr/page.do?menuIdx=512 |archive-date=5 February 2024 |access-date=12 July 2024 |website=seoulmetro.co.kr |language=ko}}</ref>
*May 22, 1992: Sindorim – Yangcheon-gu Office section opened as Sinjeong Branch
*February 29, 1996: Sinjeongnegeori Station opened as extension of Sinjeong Branch
*March 20, 1996: Kkachisan Station opened as extension of Sinjeong Branch
*October 20, 2005: Yongdu Station opened on the Seongsu Branch
*September 2010: [[Siemens Mobility]] [[Automatic train protection|ATP]]/[[Automatic train operation|ATO]] GoA 2 signalling system implemented on newer trains to increase frequencies and route capacity.