Seoul (Metropolitan) Subway Line 1 of the
Seoul Metropolitan Subway, is a
commuter rail service which links central
Seoul,
South Korea to
Soyosan Station in the northeast,
Incheon in the southwest, and
Sinchang via
Suwon and
Cheonan in the south. The central underground portion of this rail line is the oldest subway section in the Seoul Metropolitan Subway system; the entire rail line covers a large part of the
Seoul Capital Area. The underground section between
Seoul Station and
Cheongnyangni Station, which is referred to as Seoul Metro Line 1 , is currently operated by
Seoul Metro. The line first opened in 1974 partially using overground national railroad tracks from Seongbuk Station (now:
Kwangwoon University Station) to
Incheon and
Suwon Stations. At the time, the underground portion of Line 1 run by
Seoul Metro, was labeled red on maps. On the other hand, the remaining sections of the rail line run by
Korail were labeled either blue or gray on maps, and the express lines were red. In 2000, the adjacent through-running
Korail lines were officially bundled together as part of a greater Line 1, and the labeling on maps was changed to the current dark blue color. Commuter railway service was recently was extended to
Sinchang in December 2008.