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