Tires; restriction of travel under hazardous conditions; penalties.
Wyo. Stat. Ann. § 31-5-956
in effect(a) Every solid rubber tire on a vehicle shall have rubber on its entire traction surface at least one (1) inch thick above the edge of the flange of the entire periphery.
(b) No person shall operate or move on any highway any motor vehicle, trailer or semitrailer having any metal tire in contact with the roadway.
(c) No tire on a vehicle moved on a highway shall have on its periphery any protuberance of any material other than rubber which projects beyond the tread of the traction surface of the tire, except that it shall be permissible to use:
(i) Implements of husbandry with tires having protuberances which will not injure the highway;
(ii) Tire chains of reasonable proportions upon any vehicle when required for safety because of snow, ice or other conditions tending to cause a vehicle to skid;
(iii) Pneumatic tires having studs designed to improve traction without materially injuring the surface of the highway. Pneumatic tires having studs must be approved by the superintendent.
(d) The superintendent and local authorities in their respective jurisdictions may issue special permits authorizing the operation upon a highway of tractors having movable tracks with transverse corrugations upon the periphery of the movable tracks or farm tractors or other farm machinery, the operation of which upon a highway would otherwise be prohibited under this section.
(e) When the superintendent or his authorized representative determines that travel is sufficiently hazardous due to snow, ice or other conditions travel on a highway may be restricted to use only by motor vehicles utilizing adequate snow tires or tire chains, motor vehicles that are all-wheel drive vehicles or necessary emergency vehicles as defined in W.S. 31-5-102(a)(ii), including snow plows. The superintendent or his authorized representative may further restrict travel in extremely hazardous conditions to use only by necessary emergency vehicles as defined in W.S. 31-5-102(a)(ii), including snow plows, and those vehicles utilizing tire chains or to all-wheel drive vehicles utilizing adequate snow tires with a mud and snow or all-weather rating from the manufacturer having a tread of sufficient abrasive or skid-resistant design or composition and depth to provide adequate traction under existing driving conditions. The prohibition or restriction of use shall be effective when signs, including temporary or electronic signs, giving notice thereof are erected upon that portion of the highway, and it shall be unlawful to proceed in violation of the notice. The operator of a commercial vehicle shall affix tire chains to at least two (2) of the drive wheels of the vehicle at opposite ends of the same drive axle when the vehicle is required to utilize tire chains under this subsection. The state highway patrol shall cooperate with the department in the enforcement of any closing or restriction of use under this subsection.
(f) A person shall not operate any vehicle when one (1) or more of the tires in use on that vehicle is in unsafe operating condition or has a tread depth less than four thirty-seconds (4/32) inch in the case of tires which are used on the front wheels of a bus, truck or truck tractor, or two thirty-seconds (2/32) inch in other cases, measured in any two (2) adjacent tread grooves at three (3) equally spaced intervals around the circumference of the tire but the measurements shall not be made at the location of any tread wear indicator, tie bar, hump or fillet. No vehicle shall be operated on any tire that has fabric exposed through the tread or sidewall.
(g) A person in the business of selling tires shall not sell or offer for sale for highway use any tire which is in unsafe condition or which has a tread depth of less than two thirty-seconds (2/32) inch measured as specified in subsection (f) of this section.
(h) This section applies to motorcycles, motor-driven cycles, multipurpose vehicles, mopeds and off-road recreational vehicles as defined by W.S. 31-1-101(a)(xv)(K)(II) that are registered pursuant to W.S. 31-2-232.
(j) Any person who operates a motor vehicle in violation of restrictions imposed by the department or the highway patrol under subsection (e) of this section is guilty of a misdemeanor and upon conviction shall be subject to a penalty of not more than two hundred fifty dollars ($250.00). Any person who operates a motor vehicle in violation of restrictions imposed by the department or the highway patrol under subsection (e) of this section, where the result of the violation is an incident that causes the closure of all lanes in one (1) or both directions of the highway, is guilty of a misdemeanor and upon conviction shall be subject to a penalty of not more than seven hundred fifty dollars ($750.00).
(k) As used in this section, "tire chains" means metal chains which consist of two (2) circular metal loops, one (1) on each side of the tire, connected by not less than nine (9) evenly spaced chains across the tire tread and any other traction devices differing from metal chains in construction, material or design but capable of providing traction equal to or exceeding that of metal chains under similar conditions.
Source: WY Statutes (Official Site)URL: https://wyoleg.gov/statutes/compress/title31.pdfFetched: 10/4/2026