i need some insight on using the assemblies in civil 3d 2016 for a road project that involves both milling and overlaying an existing roadway and lane widening.

how would it be set up to do a 2" mill of the existing and then a 4 1/2" total overlay (2 1/2" binder and a 2" wearing course).

don't have my head wrapped around the way the assembly works, i.e. thicknesses, targets, etc.

thanks