I've been thinking about it too. I've posted a few times asking about & the main thing is the trauma caused to the train operator, & the overall mess police will have to deal with. As well as risk of failure. You can lose your legs & live, you can become a mangled mess & live - you can become completely paralyzed & live. I don't have access to high-speed trains like in Japan or the EU & UK. My only source is a freight trains, which are significantly slower than one of a bullet train meant for travel. My risk of failure is higher - so weigh that out as well - what kind of trains are near you.
I have been watching NSFL vids of train suicides to get a grip of what a decision like that may cause. A lot of the ones I have seen have been successful - but quite a few have failed with significant physical damage. You have to weigh the pros & cons, your other method options, the trains available to you - & this is not to make you feel bad, as I have been debating this method as well - but the fact that you will undoubtedly traumatize the person operating that train. You may also traumatize bystanders - you really have to think about that. I have been thinking about it as well - it's one of the biggest reasons why I'm still weighing the train method as an option for myself.