KTX services are grouped according to their route, and within the groups, the stopping pattern changes from train to train. KTX trains not deviating from the Seoul–Busan corridor are operated as the Gyeongbu KTX service. In 2004, the new service cut the route length from , and the fastest trains, serving four stations only, cut the minimum Seoul–Busan travel time from the Saemaul's 4 hours 10 minutes to 2 hours 40 minutes. With the extension of the Gyeongbu HSR, from November 1, 2010, the minimum Seoul–Busan travel time reduced to 2 hours 18 minutes, over a travel distance of . From December 1, 2010, Korail added a pair of non-stop trains with a travel time of 2 hours 8 minutes. Once the sections across Daejeon and Daegu are completed, cutting the Seoul–Busan travel distance to , plans foresee a further improvement of the four-stop travel time to 2 hours and 10 minutes.