The department or local authorities may upon application issue annual permits for the movement of semitrailers and trailers manufactured or assembled in this state that exceed the maximum length specified in section 321.457 and the maximum width specified in section 321.454. Movement of the semitrailers and trailers shall be solely for the purpose of delivery or transfer from the point of manufacture or assembly to another point of manufacture or assembly within the state or to a point outside the state; shall be only on roadways of twenty-four feet or more in width or on four-lane highways; shall be on the most direct route necessary for such movement; and shall display the special plates designated in section 321.57. All semitrailers and trailers under permit for such movement shall not contain freight or additional load. A vehicle or combination of two or more vehicles inclusive of front and rear bumpers, including towing units, involved in the movement of semitrailers and trailers shall not exceed an overall width of ten feet.