A new map from CurtSquirt - or should I say Crossfire now? This is only a provisional review, but what I was able to check out seemed all very cool - except one downstairs area with bad clipping in one corner, and no way out that I could see!
So, you have a train, as you can see in the screenshot; you also have a railway (railroad) line that goes all the way around a big, deep lake, with stations on either side of the lake. You get on the back of the train, and after a brief warning, the train sets off along the track! As far as I could tell, you can't really see all that much unless you use "fly" mode to quickly get round onto the locomotive itself, but it all really works. The train negotiates the bends at the corners rather gently, but gets up a good speed down the main straight sections.
This is an excellent use of NAB "movers", and I find I am strongly tempted to go back and explore, and ride, some more now...