Seoul Metro Line 4

Seoul Subway Line 4 (dubbed The Light Blue Line) of the Seoul Metropolitan Subway is a long line crossing from the southwest to the northeast across the Seoul National Capital Area. The central section in Seoul City is operated by Seoul Metro with some trains offering through service to Korail's Ansan and Gwacheon Lines. The southern terminus (Oido) is in Jeongwang 4-dong, Siheung City, and the northern terminus (Jinjeop) is in Jinjeop-eup, Namyangju-si, Gyeonggi-do; the newly built northern section (officially called the Jinjeop Line) is correspondingly owned by a company owned by Namyangju-si, with operations contracted to Seoul Metro. In 2022, the Seoul Metro operated section had an annual ridership of 219,587,000 or about 601,608 passengers per day.
Northbound trains that run on the Ansan and Gwacheon Lines terminate at Danggogae, except during night time where they short-turn at various stations. Southbound trains that run on the Ansan and Gwacheon Lines terminate at Oido or Ansan. All trains from Jinjeop short-turn at Sadang, though some short-turn trains to Sadang start at Danggogae or terminate one station south at Namtaeryeong.
Express train service stops at all stations between Danggogae and Sanbon, then at Sangnoksu, Jungang, Choji, Ansan, Jeongwang, and Oido. The express service only operates during rush hours on weekdays.
== History ==
1985:
:20 April: Line 4 is officially opened from Sanggye to Samseon-gyo.
1993:
:21 April: The line is extended northward from Sanggye to Danggogae.
1994:
:1 April: The line is extended southward from Sadang to Ansan when a section of the Gwacheon Line (from Seonbawi to Indeogwon) and Namtaeryeong Station open.
2000:
:28 July: The line is extended westward from Ansan to Oido.
2003
:18 July: Surisan Station opens as an in-fill station on the Ansan Line section.
2010
: Ansan Line AM express service is launched in the northbound direction only (starting from Ansan). Trains stopped at Jungang, Sangnoksu, and Sanbon, before continuing local up to Danggogae.
2014
: 1 September: Southbound PM express service is launched (terminating at Ansan). Trains make the same stops as their AM express service counterparts.
2017
: 7 July: Express service is extended to Oido. In addition to the stops they made before, trains make all stops between Ansan and Oido.
2020
: 12 September: Express service is modified, with trains now stopping at Choji but skipping Singiloncheon.
2022:
:19 March: The Jinjeop Line, a northward extension of Line 4, opens from Danggogae to Jinjeop.
=== Future ===
Express services are planned to start skipping various stations north of Sanbon station by 2023 to cut travel times.
== Stations ==
StationNumber	Station Name 	Station Name	Station Name	EX 	Transfer 	Transfer 	Transfer 	Line Name	Distance	TotalDistance	Location	Location
 	 	 	 	 	 	 	 	 	 	 	 	
 	Jinjeop (Kyungbok University) 	 	 	 	 	 	 	 	 	 	 	
 	Onam 	 	 	 	 	 	 	 	 	 	 	
 	Pungyang (2026) 	풍양 	 	 	 	 	 	 	 	 	 	
 	ByeollaeByeolgaram 	 	별가람 	 	 	 	 	 	 	 	 	
 	Danggogae 	 	당고개 	Makes all stops	 	 	 	 	 	 	 	
 	Sanggye 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Nowon 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Chang-dong 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Ssangmun 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Suyu (Gangbuk-gu Office) 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Mia (Seoul Cyber Univ.) 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Miasageori 	 	사거리 	Makes all stops	 	 	 	 	 	 	 	
 	Gireum 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Sungshin Women's Univ. (Donam) 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Hansung Univ. (Samseongyo) 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Hyehwa (Seoul Nat’l Univ. Hospital) 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Dongdaemun 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Dongdaemun History & Culture Park (DDP) 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Chungmuro 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Myeong-dong (Woori Financial Town) 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Hoehyeon (Namdaemun Market) 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Seoul Station 	 	서울驛 	Makes all stops	(Seoul Station branch) Mugunghwa-ho and ITX-Saemaeul services	(Seoul Station branch) Mugunghwa-ho and ITX-Saemaeul services	(Seoul Station branch) Mugunghwa-ho and ITX-Saemaeul services	 	 	 	 	
 	Sookmyung Women's Univ. (Garwol) 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Samgakji 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Sinyongsan (AMOREPACIFIC) 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Ichon (National Museum of Korea) 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Dongjak (Seoul National Cemetery) 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Chongshin Univ. (Isu) 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Sadang (Daehang Hospital) 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Namtaeryeong 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Seonbawi 	 	선바위 	Makes all stops	 	 	 	 	 	 	 	
 	Seoul Racecourse Park 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Seoul Grand Park (Seoul Land) 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Gwacheon 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Government Complex Gwacheon 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Indeogwon 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Pyeongchon (Hallym Univ. Sacred Heart Hospital)	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Beomgye 	 	범계 	Makes all stops	 	 	 	 	 	 	 	
 	Geumjeong 	 	 	Makes all stops	 	 	 	 	 	 	 	
 	Sanbon (Wonkwang Univ. Sanbon Hospital) 	 	 	● 	 	 	 	 	 	 	 	
 	Surisan 	 	 	 	 	 	 	 	 	 	 	
 	Daeyami 	 	 	 	 	 	 	 	 	 	 	
 	Banwol 	 	 	 	 	 	 	 	 	 	 	
 	Sangnoksu (Ansan Univ.) 	 	 	● 	 	 	 	 	 	 	 	
 	Hanyang Univ. at Ansan 	 	앞 	 	 	Suin–Bundang 	 	 	 	 	 	
 	Jungang (Seoul Institute of the Arts) 	 	 	● 	 	Suin–Bundang 	 	 	 	 	 	
 	Gojan (Korea Univ. Ansan Hospital) 	 	 	 	 	Suin–Bundang 	 	 	 	 	 	
 	Choji (Shin Ansan Univ.) 	 	 	● 	 	Suin–Bundang 	 	 	 	 	 	
 	Ansan 	 	 	● 	 	Suin–Bundang 	 	 	 	 	 	
 	Singiloncheon 	 	 	 	 	Suin–Bundang 	 	 	 	 	 	
 	Jeongwang (Tech Univ. of Korea) 	 	 	● 	 	Suin–Bundang 	 	 	 	 	 	
 	Oido 	 	 	● 	 	Suin–Bundang 	 	 	 	 	 	
 	 	 	 	 	 	 	 	 	 	 	 	
== Depots, junctions, and points of interest ==
(from Jinjeop to Oido)
* Jinjeop Depot (opening December 2024, will replace Changdong Depot for Seoul Metro-operated rolling stock)
* Turnback siding (underground) after Danggogae Station
* Changdong Depot (used for Seoul Metro class 4000, with non-revenue connection to Line 1)
* Non-revenue connecting track to Line 3 before Chungmuro Station
* Dongjak Bridge
* Chongshin Univ. – Sadang scissors crossover
* Hanyang University, ERICA Campus
* Turnback siding (underground) after Sadang Station
* Namtaeryong–Seonbawi track crossing point (flying crossover, switch from right to left-hand traffic, or vice versa)
** The voltage/current switches between DC 1,500 V ↔ AC 25,000 V
* Non-revenue crossover to Line 1 after Geumjeong Station
* Non-revenue connecting track to Seohae Line before Choji Station
* Ansan Depot (used for simple maintenance of Korail Class 341000 train)
* Siheung Depot (used for Korail Class 341000 maintenance and also for heavy maintenance of Korail Class 311000 trains operated on Line 1)
* The largest scale of shell mounds in the South Korean west coast in Oido
== Rolling stock ==
=== Current ===
==== Seoul Metro ====
* Seoul Metro 4000 series
** 1st generation, DC only: 4-01~4-26 (Restricted to Jinjeop-Sadang) 
** 1st generation, DC & AC: 4-51~4-71 (Retirement in Process)
** 2nd generation: 4-81~4-85
** 3rd generation: 4-50~4-54
==== Korail ====
* Korail Class 341000 (ex-Korail Class 2030)
** 1st generation: 341-01~341-25
** 2nd generation: 341-26~341-30
*** Trains 341-27~341-29 are temporary running on Line 3.
** 3rd generation: 341-31~341-37
** 4th generation: 341-38~341-55
*** Trains 341-31~341-34, 341-36, 341-41, 341-44~341-45, 341-48~341-55 are temporary running on Line 1.
File:20230708 서울교통공사 4000호대 3차 483편성.jpg|Seoul Metro 4000 series EMU (2nd generation)
File:Korail_Line_4_train_at_Geumjeong.JPG|Korail Class 341000 (1st generation)
File:Korail Class 341000 (2nd generation).jpg|Korail Class 341000 (2nd generation)
File:Korail341936.jpg|Korail Class 341000 (3rd generation)
=== Former ===
==== Seoul Metro ====
* Seoul Metro 3000 series (former 4000 series)
** Wide-width GEC Traction chopper resistor controlled electric car (1985–1993; transferred to Seoul Subway Line 3)
==== Korail ====
* Korail Class 1000 (Ansan Line only, transferred to Seoul Subway Line 1)
File:서울교통공사 4000호대 초퍼제어 전동차.jpg|Seoul Metro (former) 4000 series GEC stabled at Changdong Depot
File:Seoul_Metro_Line_3_train_(GEC)_arriving_at_Oksu.jpg| Seoul Metro 3000 series GEC (Former 4000 series GEC), June 2013
File:KORAIL EMU1000 2nd-First.jpg|Korail Class 1000 (2nd batch)
== See also ==
* Subways in South Korea
* Seoul Metropolitan Subway
== Notes ==
a. One of only two subway directional crossovers in revenue service in the world, the other one located between Ho Man Tin station and To Kwa Wan station of the Tuen Ma line in Hong Kong.
== References ==
 
Category:Seoul Metropolitan Subway lines
Category:Railway lines opened in 1985