how do you get a roadway object to appear as an existing element to the site model.

I am trying to create a DTM using a combination of survey and google earth data, and using tools such as the roadway (poly) to help carve and add detail into the DTM. This has all worked pretty well, except that in my siteplan it is now showing the contours in the location of the roadway as being modified per the proposed. In this project, all roads are existing, and I need them to read as such in the site plan. How do I designate that the site modifiers from the roadway are part

Thanks Allen and Miguel. I appreciate the responses! Miguel, conceptually, I think I understand what you are suggesting. In terms of a work flow or process, I am a bit confused. Do you create the roadway, update the DTM, then trace over the length of the parts using a 3d poly, cut then paste the 3d polys into the existing data of the DTM, update the model, delete the original roadway? Thanks, Jerry