I would use an Interlocking Tower to define a path for each track. Also use of the ASB by Boat works well.
Each of these options is well documented by the creator.
PG
I see you've already looked at it. This is less complicated than any other method, but you could use those too if you want. You would need 2 cubes as seen in that thread's image. Can also be used for any other number of tracks crossing each other and probably situations I have not thought of.