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.
I originally tried using power towers for supports and building around them, but it just did not look great. A lot of fooling around with beams and frames, I got something that actually worked for me. I might still somehow integrate power towers at different intervals on blueprinted platforms that match the design but it just will be redundant and another way to get around with zip lines. I just imagined an all in one transport network infrastructure plan, but just sticking with platforms for roads and trains was enough of a foundation to work off of, and really the best core to function while while extras can be worked out later.