I read your letter to e-on.  It seems to me that you are going to need to fully and exactly re-create the terrains for the geographical area in question.  Vue only allows the user to manipulate terrains in a very basic sense.  If you have to exactly re-create a terrain mass, you are going to be spending tons of time getting Vue to do what you want, and I mean tons.  Especially getting those winding roads.

I wish you good luck.

G&C