I have worked with CivilConnection for quite a while and I would like to show some things you could do with it.
The movie shows the geometry taken from the AppliedSubAssembly in AutoCAD Civil 3D and turned these into pairs in Dynamo and then a shape gets lofted between the geometry of those pairs. That shape is then turned into a family.
In this bridge example the location of the subassemblies might not be the best, but it shows what can be done. Be aware that this creates a separate family for every pair of sub assemblies and therefore increasing your project files size.