347.447347.447 Additional safety mirrors on school buses. A school bus that is painted as provided in s. 347.44 may be equipped with a supplemental mirror system, mounted on the passenger side of the school bus and designed to enhance operator visibility of children near the passenger side of the school bus, if the supplemental mirror system does not make inoperative or diminish the performance of any other mirror or safety device required on the school bus.

347.45(1)(1) All automobiles, motor trucks, motor buses, truck tractors, trailers, semitrailers, recreational vehicles, and mobile homes when operated upon a highway shall be completely equipped with tires inflated with compressed air and all other motor vehicles when operated on a highway shall be equipped with tires of rubber or of some material or construction of equal resiliency. No person may operate on a highway any motor vehicle, trailer, semitrailer, recreational vehicle, or mobile home having any metal tire in contact with the roadway, except that tire chains of reasonable proportions may be used when required for safety because of snow, ice or other conditions tending to cause a vehicle to skid, and except as provided in sub. (2) (c).

347.45(2)(2) No person shall operate on a highway any vehicle, including farm tractors, implements of husbandry, animal-drawn vehicles and road machinery, if such vehicle has on the periphery of any of its tires any block, stud, flange, cleat, spike or other protuberance of any material other than rubber which projects beyond the tread of the traction surface of the tire, except that:

347.45(2)(a)(a) Farm tractors, implements of husbandry, bicycles, animal-drawn vehicles, and road machinery may be operated with metal tires or tires having protuberances that will not injure the highway.

347.45(2)(b)(b) Tire chains of reasonable proportions may be used on any vehicle when required for safety because of snow, ice or other conditions tending to cause a vehicle to skid.

347.45(2)(c)(c) A pneumatic tire may have embedded in it wire or wire coils for improving traction on ice and snow, but such tire shall be so constructed that the percentage of wire or wire coils in contact with the roadway does not exceed, after the first 1,000 miles of use or operation, 5 percent of the total tire area in contact with the roadway. During the first 1,000 miles of use or operation of any such tire the wire or wire coils in contact with the roadway shall not exceed 20 percent of the total tire area in contact with the roadway. Tires equipped with tungsten carbide studs shall be limited in usage and design as follows:

347.45(2)(c)2.2. Such tires may be used only on authorized emergency vehicles, school buses, vehicles used to deliver mail and automobiles with out-of-state registrations and then only if such automobile is in the course of passing through this state for a period of not more than 30 days.

347.45(3)(3) The authority in charge of maintenance of the highway in question may, in its discretion, issue a special permit authorizing operation upon such highway of a vehicle the operation of which would otherwise be prohibited under this section.

347.45(4)(4) No person shall knowingly operate on any highway any vehicle on which any tire has been regrooved or recut or offer such tire for sale or exchange. This subsection shall not apply to regrooved or recut commercial vehicle tires which are designed and constructed in such a manner that regrooving or recutting is an acceptable and safe practice, nor does this subsection apply to regrooving or recutting done in a tire recapping process.

347.45(5)(5) Notwithstanding sub. (2), an implement of husbandry equipped with rubber tracks or tracks made of equivalent material may be operated on a highway if such operation will not injure the highway.

347.455(1)(1) Except as further provided in this section, no person may operate any vehicle on a highway if modifications have been made to the suspension system, axles or chassis of the vehicle which cause any portion of the vehicle to ride more than 4 inches above the height of the vehicle specified by the manufacturer. The height of the vehicle shall be measured from the level surface on which the vehicle stands.

347.455(2)(2) If the modification is for the purpose of strengthening or improving handling, modifications may be made to the suspension system, axles or chassis of a 4-wheel drive vehicle or a motor truck which has a gross weight of not more than 8,000 pounds which cause the vehicle to ride 5 or less inches above the height of the vehicle specified by the manufacturer. The height of the vehicle shall be measured from the level surface on which the vehicle stands.

347.455(3)(3) A 4-wheel drive vehicle or a motor truck which has a gross weight of not more than 8,000 pounds may be modified to use a tire and wheel size which exceeds the wheel and tire size specified by the manufacturer for the vehicle by up to 4 inches in radius.

347.455(4)(4) No person may operate any vehicle on a highway if modifications have been made to the suspension system, axles, chassis or exhaust system of the vehicle which cause any portion of the vehicle, except the tires, to extend below lines drawn from the bottom of each wheel rim to the points of contact between the tires on the opposite side and opposite end of the vehicle and the level surface on which the vehicle stands.

347.46(1)(1) No person shall operate a vehicle of the tractor type on a highway unless the driving wheels of such vehicle are protected by suitable fenders.

347.46(2)(2) No person shall operate on a highway in intercity movement any privately owned motor truck or privately owned semitrailer drawn by a truck tractor, except those motor trucks and semitrailers equipped with dump bodies, unless such motor truck or semitrailer is equipped with rear fenders or mudguards of such material and so constructed and placed as to restrict to a minimum the splashing of water, mud or other material which may be thrown by the rear wheels. Such rear fenders or mudguards shall meet the following minimum specifications:

347.46(2)(a)(a) The fenders or mudguards shall cover the tire or multiple tires they are protecting starting at the top from a line drawn vertically through the center of the axle and extending rearward and downward so that the fender or mudguard under any condition of operation or loading of the vehicle has a ground clearance of not more than one third of the horizontal distance from the center of the rearmost axle to the fender or mudguard;

347.46(2)(c)(c) If the vehicle is so designed and constructed that the rear wheels are covered in the manner specified in pars. (a) and (b) by means of fenders, body construction or other means of enclosure, then no special mudguards are required. Otherwise, the vehicle shall be equipped with special mudguards to the extent necessary to meet the requirements of pars. (a) and (b).