It's not a Trainz asset, it was created for Rail Simulator.....This is what the "read me" says in the zip -
1435 mm. and 1668 mm. for Rail Simulator and RailWorks. Switches operated by animated levers and motors.
Packaged as Rail Simulator .rpk file to ensure compatibility with both simulators.
When you are on that website, go into downloads / descargas, you need to look at the bar on the right, it will show as Select Category, click on the arrow and scroll down until you come to Auran Trainz and then find your tracks.....Most of the stuff on here I think is TRS2006, but, it's excellently created.....
Cheerz. ex-railwayman.