There certainly used to be some effort to achieve this in Outerra's Anteworld- a full earth simulation. I don't know if it ever got anywhere. There was a Google Maps overlay you could use to painstakingly add roads in their real locations. I never attempted anything elaborate, but I certainly enjoyed placing my own (non realistic) racing loops around random Scottish Lochs or Tibetan mountains and driving on them at my leisure: http://www.outerra.com