Eric Chappell, Autodesk's Civil Community Evangelist, creates a complex interchange with multiple ramps and intersections inside Infraworks.
Eric includes important advanced Infraworks model building techniques, analysis, and even export of the design to Civil 3D.
From the The Infraworks Channel and Autodesk Civil Community Playlist
and the Autodesk Civil Community Webcasts Section
Lots of important and useful Infraworks Component Road mechanics and how to crammed into an hour.