(1)    No person, without a permit therefor shall operate on a highway any motor vehicle drawing or having attached thereto more than one vehicle, except that:

      (a)    Two or 3 vehicles may, without such permit, be drawn or attached when such vehicles are being transported by the drive-away method in saddlemount combination and the overall length of such combination of vehicles does not exceed the following:

         1.    When operating on a highway designated as part of the national system of interstate and defense highways under s. 84.29, 97 feet.

         2.    When operating on a highway designated under s. 348.07 (4), 97 feet.

         3.    When operating on a highway not identified in subd. 1. or 2., 75 feet.

      (b)    Two implements of husbandry may, without such permit, be drawn by, or attached to, another implement of husbandry if the overall length of such combination of vehicles does not exceed 70 feet, or 100 feet if the vehicle combination is traveling at a speed of not more than 25 miles per hour.

      (c)    Tour trains may, without such permit, be drawn by a motor vehicle upon and along county and municipal roads and streets and across state trunk highways, and upon and along state trunk highways where there are no alternate municipal or county routes or streets for such operation. The following requirements and restrictions shall apply to tour train operations:

         1.    Tour trains shall operate within a radius of 10 miles from the situs of the beginning and ending of the excursion.

         2.    Tour trains shall operate only along those portions of the state trunk highway system approved by the department.

         3.    The towing vehicle shall be of such design and construction that it will safely tow the unit at speeds up to 35 m.p.h. and the towing vehicle shall in no case be a farm-type tractor, but shall be a motor vehicle originally designed and manufactured expressly for operation upon public highways.

         4.    Each unit of a tour train, regardless of weight, shall be equipped with brakes as provided in s. 347.35 (3) (a).

         5.    Tour trains shall be equipped with head lamps, tail lamps, stop lamps, directional signal lamps and reflectors as provided in ch. 347 and in compliance with these provisions as if the train were a single motor vehicle.

         6.    All hitches, couplings, safety chains or cables shall be in compliance with s. 347.47.

      (d)    Two trailers transporting empty pressurized or nonpressurized tanks used for hauling or storing liquid agricultural fertilizer or 2 implements of husbandry, including 2 empty trailers used primarily as implements of husbandry in connection with seasonal agricultural activities, may, without such permit, be drawn by a motor truck, truck tractor, or agricultural commercial motor vehicle if the overall length of such combination of vehicles and load does not exceed 70 feet or, if the vehicle combination is traveling at a speed of not more than 25 miles per hour, 100 feet. For purposes of this paragraph, “empty” means less than 20 percent full.

      (e)    A double bottom may be operated on highways designated by the secretary under s. 348.07 (4).

      (f)    A double bottom transporting dairy products from the point of production to the first point of processing may operate on any highway not designated under s. 348.07 (4) if the overall length of such double bottom does not exceed 60 feet. If the double bottom operates on a highway designated under s. 348.07 (4), s. 348.07 (2) (f), (fm) and (gm) applies.

      (g)    Three trailers containing only warning signs used exclusively for highway maintenance or construction purposes may, without a permit, be drawn by a motor truck if the overall length of the combination of vehicles does not exceed 60 feet.

      (h)    Two new trailers or semitrailers to be used for transporting farm products or livestock may, without such permit, be drawn by a motor truck not exceeding 25 feet in length if each trailer or semitrailer is 28 feet 6 inches or less in length and the trailers or semitrailers are being transported directly from a manufacturer to a dealer or directly from a dealer to another dealer. The length of the first trailing unit does not include a frame extension by which the 2nd trailing unit is drawn.

      (i)    A 3-vehicle combination consisting of a towing vehicle and, in order by weight, with the lighter of the towed vehicles as the 3rd vehicle in the 3-vehicle combination unless not structurally possible, a recreational vehicle or camping trailer as the 2nd vehicle, and a recreational vehicle, camping trailer, or trailer carrying any vehicle for recreational use or carrying no load as the 3rd vehicle may, without a permit, be operated on a highway if the overall length of the combination of vehicles does not exceed 65 feet and, if the total weight, including any load, of all towed vehicles exceeds 3,000 pounds, one of the towed vehicles is equipped with brakes. No 3-vehicle combination may operate under this paragraph if highway or weather conditions include heavy snow, freezing rain, icy roads, high winds, limited visibility, or upon a highway that is closed or partially closed by the department due to highway conditions.

      (j)    A 3-vehicle combination not exceeding 70 feet in overall length may, without a permit, be operated on a highway if the towing vehicle serving as the power unit is equipped with a 5th wheel and kingpin connection by which the 2nd vehicle in the 3-vehicle combination is drawn, the 2nd vehicle in the 3-vehicle combination is a recreational vehicle or camping trailer, including any combination camping-horse trailer, the 3rd vehicle in the 3-vehicle combination is a recreational vehicle or camping trailer or a trailer carrying any vehicle for recreational use, carrying equestrian equipment and equestrian supplies for recreational purposes, or carrying no load, and, if the total weight, including any load, of all towed vehicles exceeds 3,000 pounds, one of the towed vehicles is equipped with brakes. No 3-vehicle combination may operate under this paragraph if highway or weather conditions include heavy snow, freezing rain, icy roads, high winds, limited visibility, or upon a highway that is closed or partially closed by the department due to highway conditions.

   (2)   Whenever any train of implements of husbandry is being operated under sub. (1) (b), the train shall be equipped as provided in s. 347.21 (1m). Whenever any train of agricultural vehicles is being operated under sub. (1) (d), the train shall be equipped as provided in s. 347.21 (1). The trailer hitches of a train described in this subsection shall be of a positive nature so as to prevent accidental release.