Site Modeler is not available in SS3. The reality is your current license should support both SS2 and SS3 versions (IE you can install both SS2 and SS3 PowerCivil NA, or PowerInRoads / GEOPAK on the same machine if desired).. so if you want to continue with Site Modeler you can...
SS3 allows the user to use "Site Modeler" type principals in the Open Roads Technology..whether working with Roads or Site design. SS3 contains Terrains, while these may not be as automated (remember this is the first interation) they are equally as powerful in many ways.
As time permits I will try to get some site design basics together, for now the video below should give the user an Idea of what is capable with SS3.
HTH
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