I recently have been creating a Parking lot layer, from aerial photographs and lidar data. I've narrowed down my data to impermeable data but it includes some roads and some structures. I created the data into polygon form, and thought using a topology and subtracting the overlays was the most straight forward approach to removing the excess. However between strucutures and roadway overlay errors there are nearly 20,000 errors on my first of 9 sections. Does anyone know of a quicker automated way to remove the excess when I have datasets of both structure and roads to help remove the data?