Section 31-12-101 - Metal tires with projections(a) Motor vehicles, trailers and all other vehicles, contrivances or devices having metal tires shall not be operated over any of the oil, asphalt or concrete surfaced highways of the state, if the vehicle has on the periphery of any of the road wheels, any lug, flange, cleat, ridge, bolt or any projection of metal or wood which projects radially beyond the tread or traffic surface of the tire, unless the highway is protected by putting down solid planks or other suitable material, or by attachments to the wheels so as to prevent the vehicles from damaging the highway except: (i) This prohibition does not apply to tractors equipped with what is known as caterpillar treads, when the caterpillar does not contain any projection of any kind likely to injure the surface of the road; (ii) It is permissible to move farm machinery other than tractors having protuberances that will not injure the highways; (iii) It is permissible to use tire chains of reasonable proportions upon any vehicle when required because of snow, ice or other conditions tending to cause the vehicle to slide or skid.