I checked out the game World of Subways after seeing it as an example of the C4 engine, which a Cemetech member was using for one of their own projects. I was intrigued, as I love trains, and Vol. 1 simulates a train I have ridden many, many times, the PATH train between New York and New Jersey. I was impressed by the level of realism, both graphically (although the graphics are not superb, they are good enough to be immersive) and logistically. It's much more complicated than go-stop: you have a schedule and signals to follow, speed limits to maintain, etc. I definitely recommend checking it out, and I hope they continue to make new volumes.

http://www.world-of-subways.com/index.php?id=160&L=1