Seoul Subway Line 4

Line 4
Seoul Metro 4000 series EMU in July 2023 Korail Class 341000 series EMU in April 2020
Overview
Native name	4호선(四號線) Sa Hoseon
Status	Operational
Termini	Jinjeop Oido
Stations	51 26-Seoul Metro 22-Korail 03-Namyangju City Urban Corporation
Service
Type	Rapid transit
System	Seoul Metropolitan Subway
Operator(s)	Seoul Metro, Korail, Namyangju City Urban Corporation
History
Opened	20 April 1985 (1985-04-20)
Technical
Line length	85.7 km (53.3 mi) 45.3 km (28.1 mi) Seoul Metro[1] 40.4 km (25.1 mi) Korail[2]
Number of tracks	2
Electrification	1,500 V DC (Jinjeop to Namtaeryeong) 25 kV AC at 60 Hz (Seonbawi to Oido)
Operating speed	100 km/h (62 mph)

Seoul Subway Line 4 (dubbed The Light Blue Line)^{[by whom?]} 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.^[3] 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 (excluding the Jinjeop Line) had an annual ridership of 219,587,000 or about 601,608 passengers per day.^[4]

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.