> it might become more interesting to dig long tunnels under cities for these trains rather than increasing the train's maximum speed. That’s actually part of

> it might become more interesting to dig long tunnels under cities for these trains rather than increasing the train's maximum speed. That’s actually part of what the Stuttgart 21 project is doing, and why it’s so expensive (it’s not just a train station): https://en.wikipedia.org/wiki/Stuttgart_21 https://en.wikipedia.org/wiki/Stuttgart_21 They’re building several massive tunnels below the city and through the surrounding mountains to put the entire station and all rails underground, which also improves travel times on the Paris—Vienna magistrale. Being one of the first major projects of that kind in Germany, it has to deal with massive budget overruns and delays.