I believe that the CDE Xing's work correctly with the TRC system although they were built for the ATLS system. By using a script library you dont have to add a script for every crossing you make, and if you need to update the script, you only have to do it once for all the assets you make.
Feel free to use the library in your crossings as long as you are not selling them for profit. So that would leave making the .kin file for the animation.
Hope this is of some help to understand what is needed to make a crossing.
Thank you so much! So am I able to get a crossing that's already modeled (from like turbosquid or something like that) and add the script to it? And how would I add it into trainz?
Then there is the .kin file, or animation file. I have never made one from scratch.
But first you need to make a model in Blender or such that creates the 'mesh', then add things like axis so you can move pieces of the mesh that is created. The .kin file defines the movement on the axis's. A script and .kin file are required. There is no 'Turbosquid' type files available, just what is on the DLS, and you can modify if the author allows, but to make one from scratch is a master talent that very few Trainz people have.
Look up CDE XING in your CM and these are all just reskins of a true master BNSF50, and he had lots of help. If you have never created a square box static asset, I would start there, after that it starts getting complex, and others will help if you reach out.
Here is a good page to start if you use Blender, which is free;