Maria Lamas
Corridor models integrate numerous design elements of a roadway section. In major road projects, digital tools are especially critical for efficiently handling these models that bring together alignments, profiles, and assemblies.
Autodesk Civil 3D offers powerful tools for building roadway corridors and resolving design conflicts between multiple elements, simplifying the complex process of designing safe and effective roads.
In the fifth part of our learning series on roadway design with Civil 3D, we’ll cover common workflows for creating corridor models.
Increase flexibility in corridor modeling
There are several workflows for creating corridor models in Civil 3D. Before starting, superelevation must be enabled for all lanes and alignments.
Designers can choose from various corridor types – such as a divided crown with median – and modify the pivot method. They can also define the number of lanes, lane widths, and criteria for outside shoulder and superelevation. These parameters can be imported from a custom file or Civil 3D’s library of standard design criteria.
Designers can then specify the name, baseline alignment, roadway profile, and the assembly to use. All of these can be modified later, if needed.
Next, it’s time to set up the frequency of sections and key targets within corridor parameters. In the frequency menu, apply the “by curvature” option to the curves to model the corridor more accurately and avoid a segmented look in tighter areas.
Fine-tune corridor inspection with multiple views
Running and inspecting a corridor in Section Editor helps ensure accurate results.
Here, designers can check the plan, profile, section, and assembly views of the corridor, which provides multiple critical perspectives for detecting and fixing conflicts.
For example, in a curve section it may become clear that assembly lines have been defined incorrectly. This can be easily corrected by redefining parameters in the assembly view, then rebuilding the corridor model before running it again.
Around intersections, designers may want to divide the corridor into regions to ensure elements like medians or shoulders are correctly added in the model. Turning off target surfaces enables more precise adjustments, allowing designers to focus on the unique requirements of a particular region.
Civil 3D can also identify conflicts or overlaps in the superelevation calculation. In these cases, designers can manually adjust stations or right-click on the selected overlaps and choose “automatically resolve overlap.”
Intuitively create complex corridors
Some corridors utilize offset alignments. Here, designers can use feature lines or polylines to control the raised median locations.
Identifying lane names is crucial for targeting specific elements of the corridor model.
Designers can select control lines from CAD files to represent the median on both sides of the corridor. If lines extend past the median at the end of a corridor, they can be truncated by simply revising the region station limits.
To fill gaps in intersections, designers can create polylines between the sections to target horizontally, or select a center line alignment as a horizontal and vertical control.
They can then run the corridor model in the Section Editor to confirm accuracy, focusing on transition areas to be sure the assembly is behaving correctly—for example, that slopes are accurately projected.
Learn more
Large-scale road projects demand dynamic digital models for efficiency and accuracy.
See how Wayss & Freytag leveraged Civil 3D and other Autodesk tools to expand a busy highway.
Civil 3D provides the robust digital capabilities that are needed to create, test, and refine corridor models – the foundation of safe, effective transport design.
This wraps up our five-part learning series on roadway design in Civil 3D. What did you think? Are there additional topics you would like to explore in Civil 3D? We invite you to share your feedback here.
Catch up on earlier installments:
- Learn How to Design Roadways in Civil 3D, Part 1: Gathering GIS Data and Creating Surfaces.
- Roadway Design in Civil 3D – Learning Series Part 2: Roadway Alignments
- Roadway Design in Civil 3D – Learning Series Part 3: Roadway Profiles
- Roadway Design in Civil 3D – Learning Series Part 4: Assemblies and the Subassembly Composer
Learn more about Road and Highway Design using Civil 3D as part of the AEC Collection.
