The original 1991 plan for the Korea Train Express (KTX) high-speed rail system foresaw an operating speed of 350 km/h (217 mph) to enable a travel time under two hours between Seoul in the northwest and Busan in the southeast of South Korea, the termini of the first line.

[4] Later, planned top speed was reduced to the 300 km/h (186 mph) maximum of existing high-speed trains on the market.

[4] Korail then ordered high-speed trains on the basis of Alstom's TGV Réseau, the KTX-I, which started KTX service on 1 April 2004,[5] and operate at a top speed increased slightly to 305 km/h (190 mph) in November 2007.

[11] The six-year project schedule was originally set to last until July 2013, and involved 100,000 km (62,000 mi) of test runs with speeds reaching 400 km/h (249 mph).

[2] Following a call by Nam-Hee Chae, the president of the Korea Railroad Research Institute, for proposals for a generic name for Korean-made high-speed trains,[13] on 5 April 2007, Chae announced the name Hanvit (Hangul: 한빛),[14] which means a streak of intense light in Korean.

[16] Detailed designs were presented in October 2010,[1] when the prototype was expected to be completed in 2011 and start line tests in 2012.

[1] The new high-power configuration is to provide for higher acceleration:[2] the 8-car commercial configuration was calculated to reach 300 km/h (186 mph) in less than four minutes and less than 12 kilometres (7.5 mi); the top test speed of 400 km/h (249 mph) is to be reached in 673 seconds and 56.98 kilometres (35.41 mi).

[2] The development of new transformers, batteries and a number of other electric system components also focuses on reducing weight and size.

[1] The goal for maximum operating speed was originally 350 km/h (217 mph), which was expected to enable Seoul-Busan travel times of 1 hour 50 minutes.