There are generally 2 ways to get the geometry to InRoads:
1. There is an option on the elements to auto-persist which would automatically create the geometry in the Geometry Project in InRoads.
2. You can use the File > Import > Geometry > From Graphics to pick up the graphic elements and import them into Inroads as alignments. This way is not ideal but can be done. You would want to import the geometry with a good naming convention for when you go to model the roundabout or report on the geometry.
For Modeling the roundabout through Roadway Designer, you may want to check out this good PDF which will help outline the process and give good detail to the steps needed for modeling the different areas of the roundabout as well as illustrations to how the templates should be constructed.
