For purposes of this Chapter, all stops shall be made by vehicles immediately prior to entering the crosswalk closest to the intersection being approached and located between the vehicle and the intersection. Where there are no marked crosswalks but sidewalks exist, then all stops shall be made before crossing the extended edge of the sidewalk farthest from the intersection being approached. In the event there are neither marked crosswalks nor sidewalks, then all stops shall be made with the front of the vehicle located approximately at a line extended from the stop sign and perpendicular thereto into the street being traveled by the vehicle.