I remember a few years ago back in Spring of 2013 there was bad flooding and I remember several replacement buses that went on for weeks as they fixed the right of ways. That time the important lines into Austria and Italy were closed in Germany near Obersee and Traunstein. I also remember some really wonky detours in the Berlin area, I couldn't tell you the exact route we took but I'm pretty confident we went via Dessau or on some other secondary line. It was a great time to collect new and different milage.