Germans are known for being precise, and always on time. But for many years now, their trains have been chronically late. Germans are incensed, and major upgrades to the national railway system are planned. But in the meantime, their even more obsessive time-keeping neighbor, Switzerland, is thinking of excluding German trains from their network because of their tardiness. Marco Werman speaks with Christian Bottger, a professor of transportation at the University of Applied Sciences in Berlin who once worked for Deutsche Bahn.