About Exchanging Data Between AutoCAD Civil 3D and Autodesk InfraWorks
You can bring Autodesk InfraWorks data into AutoCAD Civil 3D by referencing a local InfraWorks model or an IMX file that was exported from InfraWorks. You can bring AutoCAD Civil 3D data into InfraWorks by linking to a AutoCAD Civil 3D DWG file as a data source.