California § 27454 - A tire on a vehicle upon a highway shall not have on its periphery any block, stu

§ 27454. A tire on a vehicle upon a highway shall not have on its periphery any block, stu

A tire on a vehicle upon a highway shall not have on its periphery any block, stud, flange, cleat, ridge, bead, or any other protuberance of metal or wood that projects beyond the tread of the traction surface of the tire. This section does not apply to any of the following: (a) Tire traction devices of reasonable size used to prevent skidding when upon wet surfaces or when upon snow or ice. (b) Pneumatic tires that have embedded therein wire not to exceed 0.075 of an inch in diameter and that are constructed so that under no conditions will the percentage of metal in contact with the roadway exceed 5 percent of the total tire area in contact with the roadway, except that during the first 1,000 miles of use or operation of the tire, the metal in contact with the roadway may exceed 5 percent of the tire area in contact with the roadway, but shall in no event exceed 20 percent of the area. (c) Vehicles operated upon unimproved roadways when necessary in the construction or repair of highways. (d) Traction engines or tractors when operated under the conditions of a permit first obtained from the Department of Transportation. (e) (1) Pneumatic tires containing metal-type studs of tungsten carbide or other suitable material that are inserted or constructed so that under no condition will the number of studs or the percentage of metal in contact with the roadway exceed 3 percent of the total tire area in contact with the roadway, between November 1 and April 30 of each year. A vehicle may be equipped year-round with tires that have studs that retract pneumatically or mechanically when not in use, if the studs are retracted between May 1 and October 31 of each year. A tire on a vehicle shall not be worn to a point at which the studs protrude beyond the tire tread when retracted. (2) The commissioner, after consultation with the Department of Transportation, may extend the period during which the studded pneumatic tires may be used with studs deployed or inserted in areas of the state for the protection of the public because of adverse weather conditions. (f) Pneumatic tires used on an authorized emergency vehicle, as defined in Section 165, containing metal-type studs of tungsten carbide or other suitable material, if the studs are inserted or constructed so that under no conditions will the number of studs or the percentage of metal in contact with the roadway exceed 3 percent of the total tire area in contact with the roadway. Notwithstanding subdivision (e), authorized emergency vehicles are permitted the unrestricted use of studded pneumatic tires throughout the year.