All roundabouts are created in accordance with defined rules or standards.
A number of standards are provided with the program and these may be used as the basis for your own company standards. The standards are grouped by nationality, so, for example, the UK roundabout standards are held within a file called UK_xxx.ATJ, where xxx is the most recent version of Autodesk Civil 3D 2024 that can read it, e.g. UK_890.ATJ. Additional roundabout standards are available for different markets and can even be created by users themselves. However, to ensure that the details do not change arbitrarily, there are restrictions on who can edit them. These restrictions require that users identify themselves if they wish to access a standard to make changes. No password is needed simply to use a standard.