The hidden corner was more of a challenge due to the tighter clearances under the top deck. After installing the bracing and hangers, I fabricated the curved sub deck from plywood using 37-inch outer and 32-inch inner radii (the section being a 7-inches wide). Due to the finished size, it had to be positioned into the hangers and braces in 2 pieces. I predrilled splice joint holes and attached the joiner to one side with drywall screws.

Likewise, the extruded foam sub bed was cut using the plywood curve as a template.  Here everything is in place waiting for the track.  The bus wires will be secured to the upper framing to avoid interference with passing cars.

Here is where the track will exit through a tunnel into the yard area.  Scenery will include a hillside and tunnel portals.  (The track is merely laying there as I fabricate the long sections.)