Double Decker system, lower deck for road vehicles, upper deck for trains. Still a ton of work to do, but I really enjoy the result so far. I only have the one screenshot now, and some progress pics while I worked on the blueprints (not the finalized design), but I'm on mobile, maybe I'll share some more later.
Edit: Adding linked screenshots! These are all on my test configuration while working in the blueprinter.
This is probably my biggest pet peeve about the game. You can only finagle corners by glitching foundations into each other. Just feels horrible. There are many tutorials about in on YT.
The bends were easy. I did both left and right directions a single deck, one tighter turn, one wider turn. Then stacked those prints for the second deck. The hard part was getting everything EXCEPT the foundations to line up and be coherent. I'll add homebrew light posts from blueprints to slopes and turns after placement.
It will be more of a struggle when I start figuring junctions and merges/splits into the design, having to make one item, like a t-junction, between two different prints. Even the 6x6 blueprinter may not be enough. All of my current prints were done in the 5x5.
I haven't actually BUILT out any real roads yet, but my wife and I are planning to, and were doing some blueprinting and planning. We had a lot of trouble trying to build figure out inclines. Is that something you had trouble with as well?
I'm still very much in the placing pieces as I go phase, and haven't had to deal with many inclines. However, I am aware that vehicles can handle the 2m slopes and not the 4m slopes. As long as I approach any height difference with that in mind, my slope blueprints will clear. I'm also giving myself plenty of ground clearance and will place my supports under the road to appropriately blend. Then it doesn't much matter if I'm a little higher up off the ground, but would generally like to keep it at around power tower height unless needed for the incline's sake.
I also have bottom and top slope transition blueprints as well as slopes. I can use beams from there to gauge my distances to start or properly position the slopes direction.