Dealing with geological challenges is another thing ().

...where DB's planners insist on outdated and supposedly cheap solutions that end up expensive when problems arise. Tunnels can be built in difficult geology: after all, Stuttgart itself already has the S-Bahn (rapid transit) tunnel and a light metro with several tunnels. But DB's planners didn't exactly shine in this in recent times. In addition to the tunnel with cave-crossing viaduct on the Nuremberg-Ingolstadt line, there is the Siegauen-Tunnel on the Cologne-Frankfurt high-speed line. DB first didn't want to build this line, then opted to build it (across similar difficult geology as in Stuttgart) with a supposedly cheaper excavating method, rather than some advanced alternative like a pressure-shielded tunnel boring machine. Of course the worst happened.

_{*Lunatic*, n.
One whose delusions are out of fashion.}