Along with the Seoul-Busan axis in 1970s, more than half of the population and GDP of South Korea were concentrated, and 70% of freight traffic and 66% of passenger traffic were concentrated on this axis either, which cause traffic congestion. So, the government saw the pressing need for solution to this problem. The first proposal for a second Seoul-Busan railway line originated from France and Japan which already joined in Korean metropolitan subway business. After that, the Ministry of Territory and Transportation outsourced it research to KAIST, which was committed from 1978 to 1981. The study came to conclusion that building double track railway on Seoul-Busan line is needed and a high-speed passenger railway is advisable for a new railway. A plan for construction of high-speed railway on Seoul-Daejeon line was adopted in the 5th Korean Five Year Plan.