North/South Line underground stations, Amsterdam
The regional North/South underground line is to link Purmerend north of Amsterdam with Schiphol. Phase one, the trajectory between the stations Amsterdam-Noord and Amsterdam-Zuid WTC, requires laying tubes beneath the historic central area of Amsterdam and erecting eight stations, three above ground and five below. The path of the tunnel passes at times beneath the pile foundations of existing buildings. It is for this reason that the tunnels are placed relatively far underground. The shallow station concourse is constructed as a sunk square with a glass awning. Daylight penetrates the reflecting walls and ceilings to a great depth. The station entrances are kept as close together as possible, to avoid having underground tunnels everywhere and to cleanly stitch the new line into the fabric of the city. As for the Central Station area, the new underground line is a major impetus for radically reorganizing this traffic interchange and restructuring the station square.