The first one, "Stuttgart 21" is very much related to rail. From the referenced Wikipedia article: > Stuttgart 21 is a railway and urban development project in

The first one, "Stuttgart 21" is very much related to rail. From the referenced Wikipedia article: > Stuttgart 21 is a railway and urban development project in Stuttgart, Germany. It is a part of the Stuttgart–Augsburg new and upgraded railway and the Main Line for Europe (Paris—Vienna) Regarding tunneling: > The current 17-track station is to be replaced by an underground 8-track through station.