It shall be unlawful for the operator of any truck with an overall length of more than twenty (20') feet to stop or park any such vehicle on a street which the Governing Body has designated to be within the "business district," except to load or unload, and then only when loading or unloading in an alley is impossible. Vehicles may stop or stand for a period of time not to exceed thirty (30) minutes. It shall be unlawful for the operator of any truck, regardless of length, to park said vehicle within a street intersection, on a crosswalk, in front of a private driveway, or on a sidewalk. The Governing Body may, by resolution, provide truck parking areas adjoining, or adjacent to, the business district, and when such parking areas are provided, it shall be the duty of all truck operators to use such parking areas for all parking purposes. (Ref. 60-680 RS Neb.)