(1)    No person, without a permit therefor, may operate on a highway any motor vehicle, trailer or semitrailer carrying any load extending beyond the fender line on the left side or extending more than 6 inches beyond the fender line on the right side of the vehicle.

   (2)   This section applies even though the total width of the vehicle and load does not exceed the maximum permitted under s. 348.05.

   (3)   

      (a)    Subject to par. (b), this section does not apply if the load is an implement of husbandry being transported as provided in s. 348.05 (2g) or (3m) or an agricultural commercial motor vehicle being transported as provided in s. 348.05 (3r) or (3t).

      (b)    No person may transport by trailer or semitrailer on a highway an agricultural commercial motor vehicle exceeding 8 feet 6 inches in total outside width unless the agricultural commercial motor vehicle is equipped with at least 2 amber flashing warning lamps that are lighted and visible from both the front and rear. When lighted, these lamps shall be capable of being seen and distinguished under normal atmospheric conditions during hours of darkness at a distance of 500 feet from the front and rear of the agricultural commercial motor vehicle. These lamps shall be mounted, as nearly as practicable, to indicate the extreme width of the agricultural commercial motor vehicle, but not more than 16 inches from the lateral extremities of the agricultural commercial motor vehicle.