2.4 - Add Approach Lane
Task Description:
Edit the roundabout to add slip lanes, approach roads, or move the roundabout.

AutoCAD Civil 3D 2012 User's Guide reference:
User's Guide - Corridor Modeling - Intersections and Roundabouts - Roundabouts - Editing Roundabouts

For more information watch the video below:
  • Create Roundabout (WMV)