When Level AI results are applied, Civil 3D may sometimes show irregular, jagged, or “corrupted” intersections. A common symptom is that curb return profiles don’t update properly, causing unexpected vertical geometry, broken links to offset profiles, or distorted corridor surfaces around intersections.
Typical symptoms
Curb return profiles appear “stuck” or do not respond after loading results
Intersection corridor geometry looks twisted, stepped, or inconsistent
Offset alignment / curb return profile links appear broken after a vertical change
Rebuilding the corridor does not fully resolve the issue
Most common root cause
This issue is most often caused by creating the intersection before design profiles were set to be used as the corridor vertical baselines.
If the corridor’s vertical baselines were not using the Design profiles at the time the intersection was created, the curb return profiles may not maintain proper dynamic links (especially when vertical baselines or profiles are later updated). This can lead to irregular intersection geometry after Level AI updates are applied.
Recommended fix (recreate the intersection correctly)
Follow this process to restore a clean, stable intersection:
Confirm design profiles exist
Ensure every road centerline alignment has:Existing Ground profile
A preliminary Design profile (straight-line placeholder is fine)
Set corridor vertical baselines to use the Design profiles
Use the Allsite tool (or corridor properties) to confirm each baseline is using the Design profile as its vertical baseline.Delete the affected intersection
Remove the intersection object and any associated intersection corridor regions/components created by the wizard (or manual setup).Recommended items to delete:
Corridor regions created for the intersection
Baselines associated with the intersection setup
Offset alignments
Curb return alignments / curb alignments
The Intersection object itself
Where to delete from:
From Prospector (Toolspace) by locating and deleting the intersection and its generated alignment objects, and/or
By selecting the intersection symbol in the drawing and deleting it (then confirm related objects are removed as required)
Recreate the intersection
Re-run the Civil 3D Intersection Wizard (or recreate manually using the same rules), now that design profiles and vertical baselines are correctly set.Rebuild the corridor
Rebuild the corridor to ensure all regions and targets resolve correctly.Run Level AI Results again
Load/apply results again after the rebuild. In most cases this produces a smooth, consistent corridor through the intersection with correctly updating curb return profiles.
Related: Required corridor workflow
If you’re unsure whether the drawing is set up correctly, follow the required workflow steps here:
[Link: Required workflow to create corridors for Allsite (Alignments → Profiles → Corridor Regions → Vertical Baselines → Intersections)]