While I'm familiar with train simulators, from the related videos I just discovered a weird kind of one that's completely news to me: https://www.youtube.com/watch?v=gcNTQhT5cx8
Rather than rendering in 3D, it's literally just a driver's eye video of a real train journey played at variable speed. Actually genius if you think about it - the linearity of a rail simulation makes it possible, and it's better than any renderer.