Overview
AREX is an airport rail link and commuter rail line in the Seoul Metropolitan Area of South Korea, linking Incheon International Airport and Gimpo International Airport with Seoul Station. The section between the two airports opened on March 23, 2007, and the line was extended to Seoul Station on December 29, 2010. The color used for route information for regular trains is a shade of blue called 'sea blue', while for express trains, it is orange.