I beg to differ too Kevin, the roads aren't there as game logic objects, such as in other sims where movement is created automatically, or when you place convoy in ME it adjusts the movement automatically to follow the roads (which are tpically separate objects laid on ground mesh), what we have in a poor man's solution (no pun intended towards TW) where we have points defined by terrain creator to which movement constrains. Heck the ground units have no AI on their own to avoid destroed vehicles and just move though them as these aren't there, the burniong wrecks.
Just an accademic discussion of course (but I'd love to have them like in good old CFS 3 or Il2 does)