Council may, by resolution, designate certain streets in the City that vehicles of a prescribed weight and/or size shall travel upon, and no person operating a vehicle exceeding such prescribed weight and/or size shall travel upon streets other than those designated by such resolution, except to pick up or deliver goods, wares or merchandise. In such event, the operator of such vehicle shall return to the designated route as soon as possible in traveling through or about the City. Council shall cause notices to be posted or shall erect signs indicating the streets so designated as such routes.