The train isn't especially bumpy but you do have a couple little ones here and there owing to track switches. It was not any worse than driving in a car on a typical highway. I can't speak for the bus. There may be more than one round-trip train itinerary but on ours we were not allowed off at the turnaround. It is in Canada and as long as passengers stay aboard they aren't considered as entering Canada. There was nothing but a boundary marker and if someone got off the train they said they had to call Canadian authorities which were miles away.