Intersection and Roundabout Tutorials

These tutorials will get you started working with intersections and roundabouts.


An intersection object is created from two intersecting alignments that have design profiles. During the intersection creation process, alignments and profiles are automatically generated for the offset and curb return geometry. The horizontal and vertical geometry of the offsets and curb returns is dynamically linked to the intersection object. When changes are made to the centerline alignments or profiles, the offset and curb return geometry is automatically updated.


A roundabout is created from two or more alignments that may or may not intersect. During the roundabout creation process, alignments are automatically generated for the offset and curb return geometry. The process also creates AutoCAD linework and blocks that represent traffic islands, pavement markings, and signs. The alignments and AutoCAD objects are dynamically linked to the parent alignments.

Differences Between Intersections and Roundabouts

The primary difference between an intersection and a roundabout is that an intersection is a AutoCAD Civil 3D object that is dynamic in both 2D and 3D. Profiles, corridors, and assemblies can be created automatically during the intersection creation process. A roundabout is a collection of 2D alignments that, while dynamic to one another in 2D, have no relationship in 3D. Profiles, corridors, and assemblies must be created independent from the roundabout, and they are not dynamically linked to each other or the roundabout.


All drawings used in these tutorials are available in the tutorials drawings folder . If you want to save your work from these tutorials, save the drawings to the My Tutorial Data folder so that you do not overwrite the original drawings.

For more information, see the AutoCAD Civil 3D Help topics Understanding Intersections and Understanding Roundabouts.