WisDOT surface-based point codes explained

Last updated: 2025-12-04

Starting with Civil 3D 2026, WisDOT changed the definition of the point codes in their custom subassembly library to be surface-based.

If I have an existing project with previous point codes, do I need to update my subassembly definitions?

Info:

No.

  • WisDOT will accept projects with all previous WisDOT subassembly definitions

  • All WisDOT customization packages contain all previous WisDOT sub definitions (i.e. you can rebuild WisDOT subs in an old corridor with current software and WisDOT package).

What are surface-based point codes?

Surface-based point codes have their intended surface embedded in their definition.

A typical setup for a point code would be <Surface>_<Feature>_<Direction/Quadrant/Location>_<Insertion Side>.

Surface and Feature are typically set to a default in a WisDOT subassembly/assembly.

Many common Direction/Quadrant/Location and Insertion Side can come from parameters in the WisDOT subassemblies.

Tip: For more information on this, see WisDOT subassembly automated point code suffixes explained.

The defaults set are intended for the most common/simple scenarios. Users can and are free to set their own point codes, keeping in mind the point code structure above.

Many projects may achieve unique point codes/feature lines using the subassembly defaults and dynamic point codes. Some will need project-specific codes created.

As long as the surface name is used as the initial characters, downstream tools such as Corridor - Create Corridor Surfaces will work as expected.

Tip: For more information on this, see Best practices and tools for managing code sets

What are the standard WisDOT surface-based point code prefixes?

The standard WisDOT surface-based point code prefixes created by design are:

  • Top
    • Refinement top surfaces are the full width of earthwork (left slope intercept to right slope intercept)
  • Datum (subgrade below pavement structure and top of earthwork)
    • Refinement datum surfaces are the full width of earthwork (left slope intercept to right slope intercept)
  • MarshExc (marsh excavation)
  • SGImp (subgrade improvement)
  • TopDatum is also a surface-based point code prefix. This prefix is used for where the Top and Datum surfaces coincide.
    • For rural sections, this is typically from the subgrade shoulder point out to the slope intercept

    • For urban sections, this is typically from 2FT behind the back of curb to the slope intercept

Surface-based point code examples

The following codes are intended to give some examples of what surface-based point codes could be. This is not an all-inclusive list. Defaults for all subassemblies can be found in their documentation at WisDOT subassembly help. How to use the point code suffix parameters and their special characters can be found at WisDOT subassembly automated point code suffixes explained

Point code Description
Datum_SGSP_R Subgrade shoulder point on the right side
Top_SGSP_SB_L Subgrade shoulder point of the southbound roadway on the left side
Top_Lane2_R The top edge of lane 2 on the right side
Top_CG_Terrace_SE_R The top of the curb and gutter terrace in the southeast quadrant on the right side of the baseline