I'm on the spectrum and live in a large city in Canada. I very much dislike taking the train. For me, it's due to the crowding of people, although I admit it's very nice when there are only a few people on board and I can stare at the city behind a window at night as it rolls by. Otherwise it's a very stressful experience for me that I've never been able to attenuate. I simply do not cope well with sitting and standing so close to other people, and the noises and smells are intolerable. I take the train to university. After the ride I usually need an hour or more to calm the fuck down before getting to work/going to class.

Mind you, I'm female and there have been proposed some significant differences between males and females on the spectrum, never mind the differences between any two people.