Hi @Jac 

Did you try checking our timetable? https://www.interrail.eu/en/book-reservations#/ 

In most of the cases, it will indicate when a seat reservation is mandatory or not. 

Have a nice day!

For trains in Germany, you can use the DB Navigator app or DB website to check demand. It always mentions which demand is expected a couple of days/weeks before departure on long distance services.

If it’s low or medium, don’t bother to make reservations. Plenty of seats will be available.

If high or exceptionally high demand is expected, you are best to reserve some seats. Check a couple of days before travelling to the expected demand on trains, and make reservations when demand is expected to be high or exceptionally high. For those dates I don’t really think you’ll need some, still out of high season.

Swiss railways offer a similar option, on the SBB website. Just make sure to click open the train details. But I wouldn’t worry of not finding a seat there.

(Screenshots are for trains on 9/02)

Part of your different trains, seem to be done regional trains (RB, RE, or TER) and these are not reservable what so ever. The front or back of these trains are usually calmer.

In the unlikely case you’ll find yourself standing upright, there were always people kind enough to stand up, if you explain that you have some issues to stand up for a long time.

ALL trains/wagons have seats special labelled for handicapped/pregnant ladies etc-though it varies a lot between countries how willing those sitting there will stand up.In some countries people even have special cards for that. But these immense fears in nearly ev 2nd post here about having to stand many hrs are really complete nonsense-and even more in these very weak travel periods now on. AND a tiny little bit of flexibilty might also help-on nearly all routes there is an hourly or even more frequent link.

All in all it is really not much different from how it goes in that island named GB.

Thank you both - really helpful