1

Seat reservations are only possible on the fast long-distance trains (IC, EC, ICE and the like), not regional trains and S-bahns. There are only a very few trains in Germany that can sell out as they require a seat. All others never sell out though you might not have a seat. If you are at where a train originates, arrive early and you should be able to walk through the train and find many seats. You might want to start looking a little further away from the nearest entry point if you have the time as many people who board just take the first seats available. In the past on those fast long-distance trains when we haven't had a reservation and all seats were taken, we've gone to the dining car and sat at an area for having drinks and had a few beers, much more enjoyable than spending the same money for a seat reservation for a short trip.

2

It would help if you define where you're going from/to and at what time of the week, but most trains in Germany do not require seat reservations, it's a free for all.

3

I am going in different, short and long, stages. Mostly mid-week. I was more concerned about the over-booking aspect, but I suspect it is only the airlines that do that sort of thing.

Yes, I suppose the dining car would be a good alternative.

I will be there in September, so I suppose the summer crowds will be mostly gone - except for Oktoberfest around Munich.

I am going to a conference in Vienna, then working my way to Copenhagen.

Edited by: takeitallin

4

Seat reservations are not compulsory in Germany. With the exception of the few ICE Sprinter trains and night trains. And some international service like to Paris or to Warsaw.

This means you can always board a train as they cannot book out. Seat reservations are only possible with long distance trains (IC/EC and ICE). However also on these trains not all seats can be reserved. At peak times (e.g. Friday and Sunday afternoon and evening) it can however happen that all seats are taken and some passengers have to stand or sit on the floor.

Which summer crowds? Summer vacation time is a low peak time. And DB (German Rail) throws because of this special offers on the market. E.g. between 18.06.2012 - 31.08.2012 one can get a rail pass valid 1 month which is EUR 99 for up to 18 year olds, EUR 249 for up to 26 year olds and EUR 299 for all others. Just for comparison: standard fare Munich - Hamburg is EUR 135.

5

It might help you to understand the train system if you think of it in the same way as public transport within a city -- such as taking a subway or a bus. The train system works just like that, only the rail network is bigger. No advance bookings, no reservations. You just go to a station and get on a train. That's it.

In fact, in the larger urban areas the municipal transport systems are completely integrated with the intercity networks, even using the same rail stations.

As others have said above, even for the ICE trains where you can reserve a seat, a reservation is itself rarely obligatory. Get on a train and find a free seat, or stand if none are available.

6

The Bahn website will mark those long-distance train connections which tend to be very busy with an "R" symbol (for "reservation recommended"). As mentioned above, this often concerns trains on Friday and Sunday late afternoons and early evenings.

In this case, it's a good idea to indeed buy a reservation, unless it's a short hop, or to pick an earlier or later connection which is less busy.

And to answer a question you did not ask, a good strategy for boarding if you do have a reservation (and enough time), or if you want to make a dash for the dinner car, is to check the platform for the poster (called "Wagenstandsanzeiger") showing the train's composition and at which section of the platform the different cars will be located. More detailed explanations are available on this website. Getting to a specific car is a lot easier and quicker outside the train than inside it.