Commerce and the housing sector are both proceeding apace in Amsterdam. The bus and tram network could not deal anymore with the large number of passengers (approx. 1.1 million a day). The Amsterdam Metro together with the trams is the backbone of the public transportation service in the Dutch capital.
The point of the north/south line is to connect the north of Amsterdam, where large new residential districts were arising, with the center and southern half of Amsterdam. This is where the new Amsterdam center of commerce was emerging. Two tunnels to be driven by machine measuring 3,113 meters and 3,150 meters were planned to run under the historic part of the city forming a part of a new twin-track metro line. Two Herrenknecht Mixshields with a diameter of 6,880mm have been at work since April and August 2010 respectively. Tunnelling for the first sections was completely in June and October 2010. The following sections were tunneled with a new shield and were completed successfully in September and November 2012.