Seohae Line (서해선)

The Seohae Line is a part of the Metropolitan Seoul regional metro system. It operates in western Gyeonggi-do and western Seoul. The Seohae Line is being built in four sections simultaneously. At the time of writing on 2023 the line is 47 km long with 21 stations (Ilsan-Wonsi). The first section opened on 16.06.2018. The second section in the north from Sosa to Daegok was two stages on 01.07.2023 and in 08.2023. The northern section of the line uses trackage of the suburban Gyeongui-Jungang Line.

The Seohae Line is operated by Korail, the South Korean national railway operator, but a number of stations between Sosa and Wonsi are managed by a subsidiary of Seoul Metro. The infrastructure is also owned by Korail, so the line runs on the left like the rest of the South Korean railway network.