Autodesk has released a Productivity Pack for AutoCAD Civil 3D to add more functionality. This update with increased functionality is free to all subscription customers.
The Productivity Pack includes:
Open Infraworks Model - direct sharing from Infraworks to Civil 3D to streamline the transition from conceptual to detailed design
New Co-ordinate Geometry Editor - quickly create traverse lines from different geometry and apply closures
Create AutoCAD solids - generate solids from a surface based on a depth, datum or other surface. Great for sharing forward to Navisworks and Revit. Also quickly generate solids from Civil 3D pipe networks.
You can obtain this productivity pack from the Autodesk Subscription Center. Log into the Subscription Portal from the Autodesk Subscription Page.
Once you've entered the site, click on Downloads on the left and then Product Enhancements. From the list of enhancements, download the Productivity Pack 1.