Seoul Subway Line 7

Seoul Subway Line 7 of the Seoul Metropolitan Subway was built from 1990 to 1996 (Jangam-Konkuk Univ.) and was completed on August 1, 2000 (central section 17 km (11 mi). Konkuk University to Sinpung); the western section between Sinpung and Onsu was put into service on February 29, 2000. This north-south line does not run through the city centre but links Gangnam directly to the northeastern districts of Seoul. In 2019, Line 7 had an annual ridership of 380 million or 1.04 million passengers per day. Although most trains run between Jangam and Seongnam, some trains short turn at Onsu station and some trains start at Dobongsan station.

All trains on Line 7 are monitored by 1,008 closed-circuit television cameras that were installed in June 2012.

The extension to Incheon Subway Line 1 was designed to relieve the traffic congestion in western Seoul and northern Incheon. Nine stations were added on October 27, 2012, for the 10.2 km (6.3 mi) extension, starting from Onsu Station of Line 7 and ending at Bupyeong-gu Office Station of Incheon Subway Line 1.

Line 7 was extended west of Bupyeong-gu Office. Construction on the two-station, 3.94 km (2.45 mi) extension to Seongnam began in 2013 and was completed on May 22, 2021. The extension allows for transfers to Incheon Subway Line 2.