I have a model for a sidewalk project that adds sidewalk to the adjacent roadway. the model is only for the new sidewalk and sideslope changes and does not have the existing roadway surface. the surface models are broken up between the side streets and the entire job site is not a full road way with the existing surface and new sidewalk. Due to the multiple area's and the road being horseshoe shaped down hill from STA 10+00 to STA 83+00, when i put the model into Siteworks for layout, it wants to cut a slope from STA 10+00 to the end at STA 83+00 instead of keeping the surface only at the newly defined sidewalk area's. how can i prevent this from happening so that i am not getting false grades? I have tried creating surface boundaries for the whole roadway and for around each individual new sidewalk area. Nothing has prevented this false modeling.