국가재건최고회의
Travel times increased greatly while the line was used for transport in World War II. Following World War II, the Seoul–Busan express train re-established on May 20, 1946, was named "Chosun Liberator". During the Korean War, the line transported troops and refugees. The line remained the backbone of transport in South Korea after the war, when diesel locomotives and the cross-country Mugunghwa-ho train class was introduced. Following the 1961 coup, the Supreme Council for National Reconstruction started South Korea's first five-year plan, which included a construction program to complete the railway network, to foster economic growth. On the Gyeongbu Line, the effort was advertised with a new class of express trains named "Jaegeon-ho", (Reconstruction train) introduced on May 15, 1962. These trains reduced travel times below the best pre-WWII travel times for the first time, connecting Seoul and Busan in 6 hours 10 minutes at a top speed of .