Autodesk CIVIL3D - CIVILDESIGNCOMP 2007 SLM CD Tutorials Manual page 486

Add a shoulder subassembly
1 In the drawing, pan to the left side of the LaneOutsideSuper subassembly.
2 In the tool palette, click the Shoulders tab.
3 Click
4 In the Properties palette, under ADVANCED, specify the following
parameters:
Side: Left
Use Superelevation Slope: Outside Shoulder Slope
Subbase - Use Superelevation: Outside Shoulder Slope
This sets these slopes to the outside shoulder superelevation slope. For
more information, see the subassembly help.
5 In the drawing, click the marker point at the top outside edge-of-lane on
finish grade to add the paved shoulder.
474 | Chapter 13 Corridors Tutorials
ShoulderExtendSubbase.