Trigger warning:graphic, but it answers the question for me.
The guilt/traumatizing and making other people suicidal is a pretty big issue, so it would be fine if its the main issue.
If it goes wrong its horrible. If you flinch or panic and mess up the attempt at all it can be horrible. When you get hit by a train, you don't just get thrown around and broken bones. You definitely will experience amputations. I read somewhere from an actual train experience that your flesh can start melting too which at least is going to be really painful if it happens but I cannot find that source again anyway online, it was a while ago. Either way, surviving being hit is really bad, its not hard to find stories of amputees who survived.
It's mainly traumatizing anyone on the train and any witnesses plus cleanup crews though. Somebody is going to have to walk around and find all the different body parts/bits and pieces that went flying. It's not a dignified or peaceful method. Hanging is pretty accessible, I think its the better method. Or try SN.