To have a true Preliminary to Final Design efficient workflow with Civil 3D "as advertised"... we need to have Component roads come into Civil 3D as Corridors....ready to go to work.
The lanes, curb and gutter, sidewalk, shoulders, median, and other Components in Infraworks should be mapped and automatically converted to their corresponding logical subassemblies in Civil 3D.
Such as:
Infraworks Civil 3D
Lanes >> Subassembly.LaneSuperelevationAOR
Curb and gutter >> Subassembly.UrbanCurbGutterGeneral
Shoulder >> Subassembly.ShoulderExtendAll
Roadside Grading >> Subassembly.DaylightMultiIntercept
Median >> Subassembly.MedianRaisedWithCrown
etc..