<section number="41-6a-1636"><effdate>5/6/2026</effdate><histories><history>Amended by Chapter <modchap sess="2026GS">295</modchap>, 2026 General Session</history><modyear>2026</modyear></histories><catchline>Tires which are prohibited -- Regulatory powers of state transportation department -- Winter use of studs -- Special permits -- Tread depth.</catchline><subsection number="41-6a-1636(1)">A solid rubber tire on a vehicle shall have rubber on its entire traction surface at least one inch thick above the edge of the flange of the entire periphery.</subsection><subsection number="41-6a-1636(2)">A person may not operate or move on a highway a motor vehicle, trailer, or semitrailer having a metal tire in contact with the roadway.</subsection><subsection number="41-6a-1636(3)">Except as otherwise provided in this section, a person may not have a tire on a vehicle that is moved on a highway that has on the tire's periphery a block, stud, flange, cleat, or spike or any other protuberances of any material other than rubber which projects beyond the tread of the traction surface of the tire.</subsection><subsection number="41-6a-1636(4)">In accordance with <xref depth="1" refnumber="63G-3" start="0">Title 63G, Chapter 3, Utah Administrative Rulemaking Act</xref>, the Department of Transportation may make rules to permit the use of tires on a vehicle having protuberances other than rubber, if the department concludes that protuberances do not:<subsection number="41-6a-1636(4)(a)">damage the highway significantly; or</subsection><subsection number="41-6a-1636(4)(b)">constitute a hazard to life, health, or property.</subsection></subsection><subsection number="41-6a-1636(5)">Notwithstanding any other provision of this section, a person may use:<subsection number="41-6a-1636(5)(a)">a tire with protuberances consisting of tungsten carbide studs on a vehicle if the studs:<subsection number="41-6a-1636(5)(a)(i)">are only used during the winter periods of October 15 through December 31 and January 1 through March 31 of each year;</subsection><subsection number="41-6a-1636(5)(a)(ii)">do not project beyond the tread of the traction surface of the tire more than .050 inches; and</subsection><subsection number="41-6a-1636(5)(a)(iii)">are not used on a vehicle with a maximum gross vehicle weight rating in excess of 9,000 pounds unless the vehicle is an emergency vehicle or school bus;</subsection></subsection><subsection number="41-6a-1636(5)(b)">farm machinery with tires having protuberances which will not injure the highway; and</subsection><subsection number="41-6a-1636(5)(c)">tire chains of reasonable proportions on a vehicle when required for safety because of snow, ice, or other conditions tending to cause a vehicle to skid.</subsection></subsection><subsection number="41-6a-1636(6)">Notwithstanding any other provision of this chapter, a highway authority, for a highway under its jurisdiction, may issue special permits authorizing the operation on a highway of:<subsection number="41-6a-1636(6)(a)">farm tractors;</subsection><subsection number="41-6a-1636(6)(b)">other farm machinery; or</subsection><subsection number="41-6a-1636(6)(c)">traction engines or tractors having movable tracks with transverse corrugations on the periphery of the movable tracks.</subsection></subsection><subsection number="41-6a-1636(7)"><subsection number="41-6a-1636(7)(a)">A person may not operate a vehicle if one or more of the tires in use on the vehicle:<subsection number="41-6a-1636(7)(a)(i)">is in an unsafe operating condition; or</subsection><subsection number="41-6a-1636(7)(a)(ii)">has a tread depth less than 2/32 inch measured in any two adjacent tread grooves at three equally spaced intervals around the circumference of the tire.</subsection></subsection><subsection number="41-6a-1636(7)(b)">The measurement under Subsection <xref depth="4" refnumber="41-6a-1636(7)(a)" start="0">(7)(a)</xref> may not be made at the location of any tread wear indicator, tie bar, hump, or fillet.</subsection></subsection><subsection number="41-6a-1636(8)">A person in the business of selling tires may not sell or offer for sale for highway use any tire prohibited for use under Subsection <xref depth="4" refnumber="41-6a-1636(7)" start="0">(7)</xref>.</subsection><subsection number="41-6a-1636(9)">A violation of this section is an infraction.</subsection></section>