Even in the EU there are still some difficulties. Like Finland and Estonia are on broad gauge not standard gauge. So their network isn’t connected to the rest of the EU. Spain and French haven’t connected their high speed rail network because of some dispute. So you have to get off at the border take a slow train across the border than walk to another platform to get on the other train.
Also rules says the crew needs to speak the local language of the country the train drives trough and traffic rules vary by country so if the driver doesn’t speak the language or doesn’t know the rules they need to change drivers when a train crosses a border which adds more delays.
Problem is also that there are still many rail networks in Europe that are privately owned.
Rail is hard if it’s from one country to another (I think Europe is the exception)
In my case, I have to take rail from Ankara to Edirne, Edirne to Bucharest, Bucharest to Vienna, and after Vienna I can access anywhere in Europe
The problem is, going from Edirne to Bucharest requires two visas
Even in the EU there are still some difficulties. Like Finland and Estonia are on broad gauge not standard gauge. So their network isn’t connected to the rest of the EU. Spain and French haven’t connected their high speed rail network because of some dispute. So you have to get off at the border take a slow train across the border than walk to another platform to get on the other train.
Also rules says the crew needs to speak the local language of the country the train drives trough and traffic rules vary by country so if the driver doesn’t speak the language or doesn’t know the rules they need to change drivers when a train crosses a border which adds more delays.
Problem is also that there are still many rail networks in Europe that are privately owned.
If you want to dive deeper into how rail cooperation was always hard I recommend looking into the history of the orient express