Of these stations, the respective depth of concourse and platform of A1 are 4 and 9.8 m, and the deepest station of C2 is 18.6 and 23.1 m underground. In most stations, the platform is a facing one with the exception of stations A2 and B2, which have island platforms. In a facing platform, passenger platforms are located on both sides of the tracks, whereas in an island platform, passenger platforms are located between the two tracks.