Autodesk Civil 3D 2026.1 Update

Drainage Analysis for Civil 3D 2026.1

The Drainage Analysis for Civil 3D 2026.1 extension (a separate install) provides design capabilities for Pond, Underground Storage, and Channel objects, which can then be incorporated into a comprehensive drainage system that can be analyzed using cloud-based InfoDrainage analysis services - all without leaving Civil 3D.
See the Drainage Analysis for Civil 3D 2026.1 News post for the more specific details.

Grading Optimization for Civil 3D 2026 Hotfix

There is a Hotfix for Grading Optimization (GO) 2026 available.
See the Grading Optimization 2026.0.1 Hotfix News post.

Horizontal Regression Analysis

Generate improved best fit Alignments with Horizontal Regression Analysis by selecting one or two linear data paths (COGO Points, Feature Lines, or 2D/3D polylines). The Horizontal Regression Analysis Vista displays a potential solution. Adjust the thresholds in that interface to refine the final Alignment data for creation.

Improved Surface Performance

• Performance improvements have been made when exporting a surface to a Digital Elevation Model (DEM) or Tagged Image File Format (TIFF) formats.

3D Model Viewer

The new 2026 Model Viewer facilitates high-performance and isolated 3D review of selected objects within the Civil 3D environment.

• Added interference checking in the Model Viewer.
• Implemented a switch in the interface for a Station Tracker.
• Transparency is now available in the Model Viewer.

New in Project Explorer

• Added pick buttons to select Start and End structures from a Pipe Network from the viewport. Start and End structures can still be selected from their appropriate drop-down menus.
• Improved the ability to easily scroll through long lists of structures when selecting a Start and End structure for the Profile View in the Pipe Networks tab.
• Added new items to the context menu in the Structures List view that allow any selected structure to be assigned to the Pipe Network View as a Start or End Structure.
• Right-clicking a structure now offers the following additional options:
• Assign to Pipe Network View Start Structure
• Assign to Pipe Network View End Structure.
• Added support for transposing base object table columns into rows in reports and AutoCAD tables.
• Added support to export XML data files.
• XML files added to the drop down list of file types in the Create Quick Report dialog.
• Report to XML File added to the drop-down Object Set Action list in the Create Object Set dialog box.

Infrastructure Design Review in Autodesk Construction Cloud (ACC)

The Civil Tools for Autodesk Construction Cloud (ACC) introduces Alignment awareness and civil infrastructure-specific design review workflows for ACC. The Civil Tools enhance the design review process for infrastructure projects by providing the ability to interact with models in the context of project Alignments.

Within the Docs viewer, we can navigate along alignment/profile geometry, track their position with stationing information, create perpendicular cuts to the alignments, and query the model. This allows BIM/CAD Managers, Project Managers, QA/QC personnel, and civil/design engineers, to collaborate on infrastructure projects within ACC.

New in Dynamo for Civil 3D

The nodes in the Civil 3D section of the library now include additional documentation and sample graphs to help explain how they work. To view this information, right-click on a node and then click "Help… ", or select the node and press F1.

Dynamo Core has been updated to version 3.5.2, which brings a new package publishing experience; the new Curve Mapper node, with nine different curve types; List.ReplaceItemAtIndices and List.GroupBySimilarity nodes for list manipulation; a trim boundary condition for paneling nodes, and more.

• Added a new node called Alignment.RenumberTags for renumbering tags along an Alignment according to their geometric order.
• Improved the performance of the FeatureLine.SetElevationsFromSurface and FeatureLine.SetPointElevation nodes.

See the New in Dynamo for Civil 3D 2026 page for the new added nodes and other details.

My Insights in Civil 3D

My Insights is information that is shown to you based on your usage of Civil 3D. The content is designed to be informative and actionable. See what changes have been made to drawings and who made them.

Miscellaneous Enhancements

Alignments

• Added an AutoRenumber option when using the Renumber Tags ribbon command (or EDITTAGNUMBERS on the command line). This allows for the automatic renumbering of tags. Learn more.

Cross Sections

• Added the 'Distance to Next Sample Line' property to the sample line label and the labels for incremental section data of the section data band style in the profile view.

Feature Lines

• Added the ability to right-click a feature line in the Prospector list view to select "Zoom to" and "Pan to" from the context menu.
• Added the ability to insert and delete Point of Intersection, insert and delete Elevation Point directly from canvas, when hovering over a feature line grip.

Superelevations

• Added notifications about requiring potential station adjustments when importing CSV files with Superelevation data into alignments containing station equations. Learn more.

Surfaces

• Improved surface creation from grading.

API Enhancements

• See the Civil 3D 2026.1 API Enhancements page for the specific Civil 3D API details.

Read the Fixed Issues Release Notes for Civil 3D 2026.1 Update.

Alignments

• Fixed a stability issue that could occur when a fixed spiral was added to the Alignment with Design Criteria set.

Assemblies and Subassemblies

• Fixed an issue in which Ctrl+C and Ctrl+V did not paste a copied subassembly at a specified point.
• Fixed a stability issue that occurred when using the API CorridorTransistionSet constructor. Updated API CorridorTransitionSet constructor. Seed subassembly changed from applied subassembly to subassembly from the assembly latest set for the region.
• Improved performance when opening large PKT files and changing properties in the Subassembly Composer.
• Fixed the issue that Assembly shows as AECC_ASSEMBLY in Civil 3D.

Catchments

• Improved the EPA-SWMM runoff method for Catchments by hiding the Routing Percentage field when not in use because the internal routing is set to direct.
• Fixed an issue that prevented the style selection being shown on the Catchment Properties.

Cloud Collaboration (BIM 360)

• Improved performance when opening a sheet drawing containing many sheet layouts.

COGO Points

• Fixed an issue in which Cogo Point Rollover Tooltip information was duplicated.

Corridors

• Fixed an issue of an incorrect counter in new corridor region names.
• Fixed an issue in which an incorrect value returned for QTOVolumeResult::CumulativeUsableVolume.
• Fixed an issue in which incorrect values displayed in the corridor volume report in the toolbox.
• Fixed an issue in which the elevation target did not apply when rebuilding a corridor when the elevation target was set through the API.
• Fixed an issue in which "Landscape" and "Portrait" were not translated in the dialog box when creating a slope stake report.
• Fixed a stability issue when deleting a material in the Section View Materials menu.

Cross Sections

• Fixed an issue in which a grip gizmo would not update its position accordingly when grip editing the station slider.
• Fixed an issue in which alignment child objects were being corrupted or removed, and not being carried over with the alignment when removed/moved out of a site.
• Fixed an issue in which tooltips would display duplicate/odd properties after applying changes in CUI for these tooltips.
• Fixed an issue where point markers from the Code Set Style were inserted 1 meter lower on the return segment of a U-shaped alignment in Civil 3D.

Dynamo

• Fixed an issue where the BaselineRegion.SetOffsetTargetFrequency node would not correctly set the value for offset target geometry points.
• Fixed an issue where the Baseline.AddRegion node would display a warning when adding a new region before another.
• Fixed an issue where the Parcel.UserDefinedProperties node would produce a warning when the UDPs of the parcel were used in a label expression.
• Fixed an issue where the Catchment.RunoffMethod node did not properly return the EPA SWMM and Santa Barbara Urban Hydrograph runoff methods.
• Fixed an issue where labeling nodes did not support child label styles.
• Fixed an issue where the CogoPoint.SetLabelStyle node would not allow for setting the label style to .
• Fixed an issue where label creation nodes would not work correctly when the drawing contained invalid default label styles.
• Fixed an issue where the Block.Extents node would incorrectly return null when the block definition contained certain types of invalid geometry.
• Fixed an issue where the Profile.BySurface and Profile.ByStationsElevations nodes would return null when the profile object layer did not exist in the drawing.
• Fixed an issue where the saved value for the Choose Object Type dropdown node would vary between locales.
• Fixed an issue where the Civil3D_FenceFromFeatureLine sample graph had an incorrect workspace scaling factor.

Feature Line

• Fixed a stability issue that could occur when undoing a trim command on a feature line.
• Fixed an issue in which the contextual ribbon for the feature line did not update after selecting and switching between different types of feature lines.
• Fixed an issue where there are 2 select options for feature line context menu.
• Fixed an issue that element orders are inconsistent when export feature lines to Landxml multiple times.
• Fixed an issue where Civil3D would stop working after trim and undo for several times.
• Fixed an issue where Civil3D would stop working at grip editing or moving a feature line. To apply the fix, need run audit command first.
• Fixed an instability issue when delete proxy feature lines or export to AutoCAD.
• Fixed an instability issue when import and export feature line from LandXML files.

Grading

• Fixed an issue in which grading highlights could not be removed after using the Grading Volume tools.
• Fixed an issue in which the Grading Creation tool table border did not adjust to the size of the grading creation tool dialog.
• Fixed an issue in which the Entire Group radio button was not shown as selected in the Grading Volume Tools bar.
• Fixed an issue that Civil3D would stop working when a Grading is built based on dynamically linked corridor Feature Lines.
• Fixed an issue that Civil 3D freezes when user create grading area using “Grade to elevation” criteria from outer boundary of grading area and three PG topology issues.

Gravity Pipes

• Fixed an issue in which structure/pipe label leaders were unexpectedly generated.

Miscellaneous

• Improved performance when saving a drawing with the toolspace turned on.

Model Viewer

• Fixed several issues in which right-click contextual menus did not display as expected.
• Fixed a stability issue that could occur when editing an invisible object and then closing the Model Viewer.

Parcels

• Fixed a stability issue that occured when creating a parcel segment from a line after several grip edits.
• Fix an issue in which the parcel segment label displayed information for the entire alignment after moving an alignment to the same site as a parcel.

Performance

• Fixed an issue in which objects became visible in the Model Viewer after editing even though their visibility was turned off.

Pressure Pipes

• Fixed an issue in which a pressure pipe would not follow STB Plot Style Settings.
• Fixed an issue in which a pipe hatch would unexpectedly generate.
• Fixed an issue in which "Cut Length" pressure pipe 2D length calculation was not accurate.

Profile View

• Fixed an issue in which changing the default style in the ProjectObjectsToProf setting was not reflected.
• Fixed an issue in which the Profile View Depth Label Reference was displayed incorrectly.

Project Explorer

• Fixed a stability issue that could occur when Project Explorer encountered a profile associated with more than one alignment.
• Fixed a stability issue in Project Explorer when a feature line was assigned to a site, but was also encountered as a siteless feature line.
• Fixed an issue that part of surface isn't created from grading sometimes, need rebuild grading surface if data is already corrupted.

Rail Design

• Fixed a localization issue in which the Italian version strings of the Turn Out Catalog were truncated.
• Fixed issue in which some values of Curve Radius and Lateral Acceleration labels at the beginning and end of an alignment would not display.
• Fixed a stability issue that could occur during design speed modification.

Section Views

• Fixed an issue where some objects projected to Section Views were displayed with an offset.

Subassembly Composer

• Fixed an API issue in which rearranging subassemblies inside an assembly would cause incorrect subassembly geometry results in the canvas.

Surfaces

• Fixed an issue that LandXML Export multiple alignments when corridor is in folder.
• Fixed an issue where a GEOTIFF file cannot be loaded when using the 'Create Surface from DEM' feature.

Survey

• Fixed an issue that prevented survey figures from being copied and pasted using box-select.