Recently, some colleagues and I decided to travel to a conference in Sweden by train, rather than to fly, in order to cut down our CO2 emissions. This is inline with the current university approach to travel .
This was surprisingly straightforward after a bit of research. The aim of this page is to provide useful information on how to do this as simply and cheaply as possible, which we would have appreciated when planning our trip. The main point is that train travel can be significantly cheaper if you use an interrail pass, and so the main point is explaining how interrail passes work.
 Man in Seat 61
 Rail Europe
 Trains vs Planes
See if there if your destination is listed on . This can be very useful and provide tips for your route.
Use  to look at specific train times and plan the journey.
Work out if it is cheaper to buy tickets directly from  or to use an Interrail pass.
How Interrail Works:
This is listed in good detail here, but here is a guide to work out the price of a trip using an interrail pass:
You can buy a "Global Interrail Pass" which will cover a certain number of days of travel in a given period. For example, for most trips the "4 days within 1 month pass" is sufficient. Let's suppose we have bought this pass.
With this pass, once activated, you have 4 days within the following month for which you can use the pass. These days don't have to be decided when you activate the pass, so it is quite flexible. On the days the pass is valid, you get free unlimited travel on trains within Europe.
However, some journeys require "reservations". These normally only cost a few euros, and guarantee you a seat. The one exception is Eurostar, which costs £30 for a reservation. The trains that reservations are required on are typically the long distance trains. To check which trains need reservations you can search here on . This link is the simplest way to book reservations. On some trains they are optional, and for some trains reservations don't exist as a concept. One can book them on each train provider's website directly, which can be slightly cheaper, but quite a bit more faff.
Then simply add up the cost of the interrail pass and the various reservations required, and compare this to the face value ticket costs from .
N.B. Eurostar reservations for interrail often sell out. Unfortunately, on the interrail webstite  one needs to have first bought an interrail pass before one can check if there are any eurostar reservations remaining. In order to get around this and check the availability of eurostar reservations for interrail, use  instead.