|Line length||23.3 km (14.5 mi)|
|Number of tracks||2|
The Sosa–Wonsi Line is being built in four sections simultaneously. The line will run south from the existing Sosa Station in Bucheon, cross Siheung, and end in Wonsi New Port in Ansan. The section will have transfer stations with the Seoul Subway Line 1 at its start in Sosa, with the Sin Ansan Line at Siheung City Hall, and with Seoul Subway Line 4 in Ansan. There will be altogether 12 stations on the 23.3 km (14.5 mi) line.
After the completion of planning, the project was written out as a build-to-lease (BTL) project, and Daewoo was selected as preferred bidder in September 2008. Construction was scheduled to last from October 2009 to March 2013. Due to the global financial crisis, it was difficult to gather investors to finance the project, and negotiations stalled. An agreement was finally signed on December 21, 2010, with construction set to start in the first half of 2011. Project costs are 1.5248 trillion South Korean won, the contractor has altogether seven years for design and construction, and will manage and maintain the line for the first 20 years of operation.
The following list of stations may be subject to change as the line is constructed.
|Sosa||소사||素砂||Daegok–Sosa Line (2021)||
|Siheung City Hall||시흥시청||始興市廳||New Ansan Line (2023)|
|Hwarang or Choji||화랑 or 초지||화랑 or 草芝|
Tentative plans foresee the upgrade and incorporation of the Gyowae Line, currently a single-track non-electrified line without passenger service that connects Neunggok Station (with a junction just before Daegok Station) and Uijeongbu Station in Uijeongbu. The Uijeongbu–Daegok–Sosa–Wonsi Line would then provide orbital metro service as a northern semicircle around Seoul, complementing the southern semicircle formed by the Bundang Line and the Suin Line.
On September 1, 2010, the South Korean government announced a strategic plan to reduce travel times from Seoul to 95% of the country to under 2 hours by 2020. As part of the plan, the Sosa–Wonsi Line is to be further upgraded for 230 km/h, the Wonsi–Hwayang extension is to be projected for 250 km/h, and the line may see KTX service.
- "서울 접근성 높인 소사원시선 역세권 아파트 'e편한세상 시흥'" (in Korean). Asiae. 2016-12-21. Retrieved 2017-01-13.
- 소사~원시 복선전철 내년 상반기 착공예정 (in Korean). The Chosun Ilbo. 2010-12-21. Retrieved 2010-12-30.
- Daewoo E&C Financial Statements 2008
- Daewoo E&C Non-Consolidated Financial Statements December 31, 2008 and 2007
- "South Korea's growing network". Railway Gazette International. 2008-09-08. Retrieved 2010-08-29.
- "Bullet trains coming to a town near you by 2020". JoongAng Daily. 2010-09-02. Retrieved 2010-10-27.