Ensure connectivity, direction and numeration of the roads. We must use the exact format. We must make sure that the road number is correct. GIS files and aerial photos, among other things, will be useful to do so. Be careful when you delete a segment. Even if this does not exist in the GIS files, reality says that it can exist and be a new road. If you have any doubts, please contact your group leader. Only delete a segment when you're absolutely sure that it does not exist. If there is a bridge on a road, add it. See chapter "elevation" of this wiki. Add the PLR (Parking Lot Roads) of the shopping malls and drive-thru. Add U-turns where needed. This is not an exhaustive list ! If you see a further problem, fix it !