Roads created in Autodesk Civil 3D are known as corridors. Civil 3D corridors can also represent other features such as pathways, retention walls, breakwaters, berms, etc. The horizontal control lines of such corridors are known as alignments. In many cases they represent the centerline of the road, but may also be medians, curblines, etc. depending on the design.
Civil Alignments are part of Civil 3D drawings. When opening or appending a Civil 3D drawing (which contains corridors built with alignments) in Navisworks (2024 and up), the Civil Alignments tools allow you to drive along a corridor from a driver’s point of view. There are a variety of controls you can set to meet viewing requirements you may have.
Note: To access these Civil Alignments in Navisworks, you need to have either Civil 3D, or the Civil 3D enabler installed.
The Civil Alignments window
In Navisworks, the Civil Alignments window allows you to "drive" along an alignment simply by pressing the Play / Pause button. It also contains many options and settings to control the camera position and navigation through the scene relative to the civil alignment.