Component road assemblies have the ability to transition in or out along the same assembly, but as far as I know there is no way to transition between different assemblies. It would be helpful if this feature was added.
One application would be transitioning between attached and detached sidewalks. By "attached" I mean that the sidewalk is directly behind the curb, and by "detached" I mean that it is separated from the curb by a landscape planter/swale. I do a lot of residential design, and this is part of nearly every project.
I'm sure that there would be many other applications of this feature as well.