Civil 3D makes quick work of building Assemblies using its pre-built library of subassembly parts. As each “road part” is dragged from the Tool Palettes to an Assembly, Civil 3D assigns it a generic name. By default, the assigned names will match the part names shown on the palettes, thus filling your Assemblies with components called “LaneSuperelevationAOR”, “UrbanCurbGutterGeneral”, or “DaylightStandard”.
As Assemblies become more complex and involve the targeting of surfaces, alignments and profiles, these generic subassembly names can make it nearly impossible to tell components apart. In fact there is nothing more frightening than a Target Mapping dialog box that looks like this…

At times like these we have no choice but to visit the Assembly Properties and begin the painstaking process of logically naming each subassembly component.
Fortunately, managing subassemblies doesn’t have to be painful. If you are a “Subassembly Naming Procrastinator” like me, you may appreciate a Civil 3D setting that reminds you to name subassembly parts as they are added to the drawing.
Here’s how it works…
Step 1. On the Settings Tab of the Toolspace, expand the Subassembly category followed by the Commands group.
Step 2. Right-click on the CreateSubAssemblyTool command and select “Edit Command Settings” from the menu.

Step 3. In the Edit Command Settings dialog box, expand “Subassembly Options” and click in the Value column next to “Subassembly Name Prompt” to turn the feature on.

Step 4. Click OK to close the dialog box.
From now on, each time a subassembly is added to the drawing, Civil 3D will pause allowing you to give the component a logical name.

If a design involves complex corridor modeling, there is a certain peace of mind that comes from knowing your subassembly components are well organized and logically named. By making a simple tweak to Civil 3D’s command settings, you may never again have to sift through a “crime scene” Assembly in an attempt to identify all of the pieces.
-Jeff