After excluding the Seoul metropolitan area, it was the fourth subway line created in South Korea, following Busan, Daegu, and Gwangju.

2029 is the tentative opening date of a 14-kilometre (8.7 mi), five-station extension from Banseok to Government Complex Sejong in the neighbouring Sejong City.

[3] In 1991, the Daejeon Metropolitan City Urban Railway Construction Plan was established.

The subway construction headquarters was established in April 1996, and construction of the first line of Daejeon subway line was started in October of the same year.

[4] This article relating to rapid transit systems in South Korea is a stub.