For double height trains however go a bit slower, I think. In the denser populated Europe, with tracks shared with passenger service that is an issue as overtak

For double height trains however go a bit slower, I think. In the denser populated Europe, with tracks shared with passenger service that is an issue as overtaking them takes even more infrastructure and regular stopping and accelerating again. Whereas in US there are large parts where they can simply go their speed for a long distance, which makes it really efficient.