Now that there are vanilla train rails in SE, a version of this that incorporates them would be *very* much welcomed, as there is no more efficient way to move bulk items long distances fairly quickly. I'm picturing the sections as having a sloped concrete base with flat bottom sections so that other concrete blocks can be used to build it up. As trains can safely go a *lot* faster than other ground vehicles, the curves would need to be *much* more gradual--a *slightly*-banked 8x8 that turns through 45 degrees would probably work well. Of course, that would also mean needing 45-degree versions of the other track pieces, but that would be a *GOOD* thing. (Those pieces don't need to be flat on the ends; Factorio diagonal rail pieces come to a point to match the grid and that works perfectly fine. A short piece with a flat end--and optional buffer stop--would be good enough for aesthetics.

Does that make sense?

P.S. Bonus fake internet points if you also come up with powered trucks--3x3x1 small-grid with unsuspended flanged wheels and a rotor head in the centre--that makes building train cars simple by just placing a downward-facing rotor at each end.