In 1990 subways were gradually replacing buses as the main means of transportation in Seoul. The Seoul subway, the first part of which opened in 1974, was operated by the Seoul Metropolitan Rapid Transit Company. In 1985 the system carried approximately 3 million passengers daily. In 1990 the subway had more than 200 kilometers of track, enabling commuters to reach any station within the 45-kilometer radius of the capital city within an hour. One line connected Seoul with Inch'on. Four subway lines served Seoul, in addition to the lines of the Korean National Railroad.

South Korea has an excellent railroad network. The first railroad, which linked Seoul and Inch'on, was opened in September 1899. Other major lines were laid by the Japanese during the colonial period these included lines originating in Mokp'o, Masan, and Pusan. These lines connected to Seoul and to Sinuiju in North Korea, where they were linked with the Trans-Siberian Railway. The railroad network was badly damaged during the Korean War, but it was later rebuilt and improved.

Throughout the 1970s and 1980s, the Korean National Railroad, a state-run corporation under the Ministry of Transportation, was in charge of all rails and continued electrifying heavily used tracks and laying additional tracks. As of 1987, the combined length of the country's railroad network was approximately 6,340 kilometers, including approximately 761.8 kilometers of doubletrack railroads and 1,023 kilometers of electric railroads. Suburban lines were electrified and connected to the Seoul subway system. Rolling stock included 459 diesel locomotives, 90 electric locomotives, 133 motor coaches, and 370 electric motor cars. In 1989 Seoul announced that it was studying the possibility of constructing high-speed railway systems similar to those in Japan and France.

Railroads in the 1980s were useful primarily in the transportation of freight, but they also were important for passenger traffic around Seoul and in the heavily-traveled corridor linking the capital with the southern port of Pusan. Although the railroad system grew little during the 1980s (there were already 5,600 kilometers of tracks in 1980), rail improvements--the increased electrification of tracks, replacement of older tracks, and the addition of rolling stock-- allowed rail traffic to boom. Some of the busiest lines south of Seoul linking the capital with Pusan and Mokp'o had three or four tracks. The 1980s also saw the introduction of high-speed trains connecting Seoul with Pusan, Chonju, Mokp'o, and Kyongju. The famous "Blue Train" between Seoul and Pusan (via Taejon and Taegu) took only four hours and fifty minutes and offered two classes of service, first class and special. In 1987 approximately 525 million passengers and 59.28 million metric tons were transported by the railroad system.

Data as of June 1990