2 dead (both United Pacific employees, I assume train crew) and 3 light injuries from a train crashing into a truck, derailing, and hitting a building I think is pretty good evidence that using a train as your kinetic delivery is not a great way to do terrorism.
In all those examples trains are no different than movie theaters, malls, markets, sport and music events, etc. i.e: just places where large groups of people gather.
https://spectrumlocalnews.com/tx/south-texas-el-paso/news/20... a train crashed into the chamber of commerce building in Pecos Tx 5 days ago.