Great Train eXpress (GTX) is a higher-speed commuter rail network in the Seoul Metropolitan Area project consisting of three separate lines, named GTX-A, GTX-B and GTX-C, and scheduled for completion in 2030.

[3] However, the project has been officially delayed due to land compensation issues and the discovery of archaeological ruins dating from the Joseon period.

[4] The line currently runs in two separate sections - Dongtan to Suseo and Unjeongjungang to Seoul Station.

[9] Approximately 30 km (19 mi) of the line are expected to share the same rail as the SRT, and an additional 9 km (5.6 mi) towards the western end of the route are expected to be completely underground.

Plans for a Line G and H that will expand to the northern and southwestern regions of Gyeonggi Province have also been announced.