You could use the full intersection to cover NEARLY the entire application. And if all styles and object were done from scratch as suggested then you might suggest the reader might achieve mastery.
Lets see, Importing survey data from a field book for existing conditions. Or importing points, with descriptions, and label styles.
Or importing a surface from TIN, or DEM could also be shown.
If your 'intersection' scenario where to be approximately 1000 units long you could expose them to Templates that do NOT transition and those that do. You could include Offsets for bus bays/turnlanes and medians on at least one of the intersecting streets. You could include Alignment creation, and editing tools. Profile creation/editing tools explain the pitfalls of the targeted profile needing to be as long as the parent alignment early. Show them importing profiles from text files, and copying them. Show them how they can or should create a dummy corridor surface and include that surface in a profile to use as a design aide. Show them the toolbox, and the various alignment reports they can create. Have them build all the assemblies as required for the above, include Daylight targeting , and perhaps a drainage feature. Show them some replacement or new pipesconstruction. Finish it all off with Materials reports, and sheets creation. To give them a bigger picture of how it all works together starting with nothing other than the default acad.dwt.