(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).
(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:
- (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.
- (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.
- (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:
- The department shall, by rule, designate the times of year during which any type of tire described in this paragraph may be used.
- 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.
- Such studs shall not project more than one-eighth inch beyond the tread surface of the tire.
(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.
(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.
(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.