People sometimes ask if it’s just greenwashing to pledge not to fly short-distance as a researcher. But when I travelled to Vienna (~700km by car from Potsdam) last month for a talk, I would’ve normally just booked a flight. Flying would be faster, cheaper, and booking the flight would be easier. Plus, I would save at least one overnight stay.
But since I had pledged not to fly, and since Vienna is reachable in about 10 hours by train, I decided to take the train instead. The way there was relatively unremarkable. I had to switch trains in Berlin as always, but then was able to take a direct ICE from Berlin to Vienna, 10:05-17:45. The train wasn’t full (my neighboring seat wasn’t taken most of the ride) and the internet worked. But the train was so fast that part of the way I felt train sick and couldn’t read or type.
For the way back, I had decided I didn’t want to stay overnight again because it’s expensive and because I didn’t want to spend all Saturday on a train again. So I booked the NightJet by ÖBB, 22:10-9:16 the next day. You have to book it on a separate site, which I found bothersome. It’s extremely cheap (39 Euros for the cheapest option) but I booked a 4-person „Liegewagen“ (cot wagon) for extra. I ended up having the compartment to myself, and I got sheets and a pillow (I had brought my own pillow just in case). The night train takes a circuitous route through Poland (Wrocław), but it was fine because I was mostly asleep. The ride was comfortable, though I wished I had brought ear plugs against the noise, and a sleep mask because the window didn’t have blinds. At 8am we got served breakfast and we arrived about half an hour late in Berlin.
ÖBB just advertised their new NightJet trains they are building, so that might make the trip even nicer soon.
Bed 
Breakfast 
My train car 
4-cot compartment 
New ÖBB NIghtJet