CA Veh Code § 24603 (2021)
2021 California Code|Vehicle Code - VEH|DIVISION 12 - EQUIPMENT OF VEHICLES|CHAPTER 2 - Lighting Equipment|ARTICLE 3 - Rear Lighting Equipment|Section 24603.

24603.  Every motor vehicle that is not in combination with any other vehicle and every vehicle at the end of a combination of vehicles shall at all times be equipped with stoplamps mounted on the rear as follows:(a) Each vehicle shall be equipped with one or more stoplamps.(b) Each vehicle, other than a motorcycle, manufactured and first registered on or after January 1, 1958, shall be equipped with two stoplamps, except that trailers and semitrailers manufactured after July 23, 1973, which are less than 30 inches wide, may be equipped with one stoplamp which shall be mounted at or near the vertical centerline of the trailer. If such vehicle is equipped with two stoplamps, they shall be mounted as specified in subdivision (d).(c)  Except as provided in subdivision (h), stoplamps on vehicles manufactured on or after January 1, 1969, shall be mounted not lower than 15 inches nor higher than 72 inches, except that a tow truck or a repossessor’s tow vehicle, in addition to being equipped with the required stoplamps, may also be equipped with two stoplamps which may be mounted not lower than 15 inches nor higher than the maximum allowable vehicle height and as far forward as the rearmost portion of the driver’s seat in the rearmost position.(d) When two stoplamps are required, at least one shall be mounted at the left and one at the right side, respectively, at the same level.(e) (1) Stoplamps on vehicles manufactured on or after January 1, 1979, shall emit a red light. Stoplamps on vehicles manufactured before January 1, 1979, shall emit a red or yellow light.(2) Paragraph (1) does not apply to commercial motor vehicles, as defined in Section 15210 or 34500. Stoplamps on a commercial motor vehicle shall emit red light. A commercial motor vehicle shall not be equipped with an amber stoplamp, amber taillamp, or other amber lamp that is optically combined with a stoplamp or taillamp.(f) All stoplamps shall be plainly visible and understandable from a distance of 300 feet from the rear of the vehicle both during normal sunlight and at nighttime, except that stoplamps on a vehicle of a size required to be equipped with clearance lamps shall be visible from a distance of 500 feet from the rear of the vehicle during those times.(g) (1) Stoplamps shall be activated upon application of the service (foot) brake and the hand control head for air, vacuum, or electric brakes. In addition, all stoplamps may be activated by a mechanical device designed to function only upon sudden release of the accelerator while the vehicle is in motion. Stoplamps on vehicles equipped with a manual transmission may be manually activated by a mechanical device when the vehicle is downshifted if the device is automatically rendered inoperative while the vehicle is accelerating.(2) For an autonomous vehicle, as defined in Section 38750, that is not capable of operation by a human driver seated in the vehicle, stoplamps shall be activated upon the remote or autonomous activation of the braking system, provided that this modification is consistent with, or authorized by, any applicable federal law, regulation, or exemption thereto.(h) (1) Any vehicle may be equipped with supplemental stoplamps mounted to the rear of the rearmost portion of the driver’s seat in its rearmost position in addition to the lamps required to be mounted on the rear of the vehicle. Supplemental stoplamps installed after January 1, 1979, shall be red in color and mounted not lower than 15 inches above the roadway. The supplemental stoplamp on that side of a vehicle toward which a turn will be made may flash as part of the supplemental turn signal lamp.(2) A supplemental stoplamp may be mounted inside the rear window of a vehicle, if it is mounted at the centerline of the vehicle and is constructed and mounted so as to prevent any light, other than a monitorial indicator emitted from the device, either direct or reflected, from being visible to the driver.(i) Any supplemental stoplamp installed after January 1, 1987, shall comply with Federal Motor Vehicle Safety Standard No. 108 (49 C.F.R. 571.108). Any vehicle equipped with a stoplamp that complies with the federal motor vehicle safety standards applicable to that make and model vehicle shall conform to that applicable safety standard unless modified to comply with the federal motor vehicle safety standard designated in this subdivision.(Amended by Stats. 2021, Ch. 428, Sec. 4. (SB 570) Effective January 1, 2022.)