This 12d tool is used to create a special chainage file for any alignment/super alignment string.

The chainages are created for a selected reference string but can then be defined by dropping strings and/or individual points onto the reference string.

The option will re-organise the chainage order to ensure they increase for you.  The list can be cleared, read from an existing file and added to as your design develops.

To create multiple “special chainage files” for your project, skip forward in the video (6:30min) to have a look at the global 12d tool to help with this process.

To view the “Special Chainage File” panel,

Use: Design => Roads => More => Special Chainage File