https://en.wikipedia.org/wiki/Longest_trains https://en.wikipedia.org/wiki/Longest_trains gives 180 cars for the US, and longer for Australia, Brazil, and other

https://en.wikipedia.org/wiki/Longest_trains https://en.wikipedia.org/wiki/Longest_trains gives 180 cars for the US, and longer for Australia, Brazil, and others. Cars can also have more than four axles; at the extreme you have https://en.wikipedia.org/wiki/Schnabel_car https://en.wikipedia.org/wiki/Schnabel_car But yes, this is probably not an issue in Europe.