What Is the Nature of California’s Third Brake Light Law?
A detailed overview of the legislative background of California’s third brake light law, including when this law was enacted and its primary purpose in statewide road safety legislation. Since 1986, California has required vehicles to be outfitted with a third brake light that will illuminate when drivers hit the brakes. The law, found in the California Vehicle Code, Section 24603, is written to keep pace with the state’s high-traffic roadways, combat distracted driving and encourage safer, more responsible driving across California. While the law is not yet universally adopted in every state, California was ahead of its time when it enacted third brake light regulations in the mid-1980s. According to the Center for Auto Safety, the measure has been shown in studies to reduce rear-end collisions, something in which the CFS had previously lobbied for adoption by the federal government . The organization helped the National Highway Traffic Safety Administration adopt the regulation as a national law in 1986. The law mandates that third brake lights, often referred to as center high mount lights (or CHMs), are located at least 35 inches above the road and are between 3.5 and 8.5 inches in height, according to Section 24603 of the California Vehicle Code. Studies show third brake lights to be much more visible to other drivers when traveling at higher speeds, such as those experienced on freeways and other fast-moving roadways. While seldom held accountable when rear-end crash cases go to court, rear-end accidents are still among the most frequently reported on California courts of law. Third brake lights are seen as a tool to help slow or prevent preventable accidents on the roadways.
Obligations of Vehicle Owners
The Vehicle Code requirements for when a vehicle needs a third brake light are:
- (a) A vehicle, except a motorcycle, trailer, semitrailer, pole trailer, or truck tractor, that is not equipped with an electric third brake light or a third brake light that is a part of a powered lift, or a passenger vehicle as defined by Section 465 of the Vehicle Code, shall adhere to the following:
- (1) Beginning July 1, 1976, a passenger vehicle registered in this state shall be equipped with a center high mount stop lamp. This center high mount stop lamp shall consist of a single filament lamp, or one or more arrays of light emitting diodes (LEDS), or a combination of both, and shall be activated in conjunction with the braking system of the passenger vehicle. Any other design of center high mount stop lamp system which has been approved by the commissioner is also acceptable. The center high mount stop lamp shall be placed as high as practicable, but not more than five inches below the center of the bottom of the window glass and shall not obscure any symbols, letters, or numbers on that glass.
- (2) A passenger vehicle which was manufactured for model year 1988 or later, or which was manufactured in the aftermarket with a center high mount stop lamp that meets the requirements of either the American National Standards Institute or the Society of Automotive Engineers shall not be subject to the testing of this section.
If your center high mount stop light system fails, you will likely be pulled over by law enforcement officer and issued a fix-it ticket. It is important to remember that you do not have to pay a fine; you merely have to get the system repaired and take your vehicle to a station that has an official certified by the state to sign off on your fix-it ticket. If you have any questions about whether your vehicle has failed the third brake light inspection requirement, consult with an experienced traffic citation attorney.
Specifications on Installation and Maintenance
Practically speaking, the installation and maintenance of third brake lights involves both placement and brightness of third brake lights within the defined limits of California law. The requirements set forth under the California Vehicle Code are instructive, but do not go far enough in establishing clear guidelines for three-dimensional brake lights. For example, it lacks an explicit mention or bright-line definition of a three-dimensional structure. However, this requires no divine insight to coax out, but rather a simple look at the amendment history of sections § 24600(e) and § 24003 in the code. These sections were amended to include the expression "three-dimensional." Logically this means that there is a class of "one-dimensional" brakelights as well.
The Vehicle Code defines a "three-dimensional" object for the purposes of third brake lights as a "structure of three dimensions having height, width, and depth." The three-dimension element of the definition suggests that the assembly must extend outwards in some manner from the flat surface to which it is anchored. As a general rule, if the brake light assembly is flat, and has no depth, then it is a "one-dimensional" light fixture, and possibly an assembly consisting of just one or multiple two-dimension lights.
The code requires that all third brake lights have a certain angle of scope, brightness requirements, and a need for periodic maintenance. The California Vehicle Code § 24600 is concerned with the "scope" of third brake lights, whereby "scope" is basically defined as the angles of visibility for third brake lights. A complete failure of scope would result in a volume in which the brake light could not be seen, whether it be state or stationary. Thus, the requirement not only applies to the third brake lights as seen from the front or back of the vehicle, but also the sides, since careless vehicle operators can operate their vehicles such that a third brake light falls outside of the acceptable viewing areas.
The general rule is that all third brake lights need only be "visible from a distance of 300 feet to the rear" and "at a distance of 500 feet at a 30-degree angle." In contrast, in the case of standard (rectangular) taillights, Section 24600 requires that they be visible from a distance of 500 feet to the rear, and 1,000 feet at a 20-degree angle.
To conform to the standards of Visibility outlined above, third brake lights, and any other type of rear lighting, are subjected to the regulations of Section 24000 (c)(d), where the basic requirements of lights deems them unlawful unless "displayed only when the [vehicle] displays its headlights to the front or any of its turn signal lamps or its parking lamps, taillamps or stop lamps display. . ." So, as a general rule, for most vehicles, if a vehicle has rear lights of any kind, they are considered taillights under section 24000, and thus, they must be displayed when their headlights are displayed. If a vehicle is displayed without headlights (or the rear lights are displayed without the headlights), even if the headlights are not obstructed or covered by any other object, the brightness of the third brake light is irrelevant. Rather, all of the lights on the vehicle need to be displayed. Therefore, the third brake light, and its compliance with the brightness requirements of section 24003, will depend upon the distance of scope, and thus the position of the vehicle and other objects around it.
Penalties for Non-Compliance
Section 24603, commonly known as California’s third brake light law, is a requirement that all motor vehicles manufactured after 1986 must be equipped with a working high-mounted center brake light. These lights are often referred to as "third brake lights," and they are a valuable safety device —come to think of it, it is that extra light that is also responsible for a very significant percentage of rear-end collisions. Nonetheless, not everyone complies with this requirement , and there are still a fair number of old cars on the road that do not have a third brake light.
So what happens if your vehicle does not comply with this provision? The main issue will be at the time of inspection (an initial inspection or a biennial inspection). In this context, your vehicle may be rejected (if a first or biennial inspection is required) until proper compliance is ensured, meaning you would need to have the required lighting or brake lights (on top of those already present) added to your vehicle, thus causing some additional and unnecessary expense.
In addition, anyone who knowingly drives a vehicle that is not compliant would face penalties of $250 as a base amount, though the penalties could increase depending on the circumstances.
Significance of Third Brake Lights for Highway Safety
The third brake light, also known as the center high-mounted stop lamp (CHMSL), is an essential component of modern vehicular safety design. While having only been added as a federal requirement in 1986, its impact on reducing rear-end collisions has been substantial. According to a study undertaken by the National Highway Traffic Safety Administration (NHTSA) in 1992, the introduction of the third brake light reduced the risk of a rear-impact crash by 4 to 5 percent for cars and 10 to 12 percent for light trucks.
Modern third brake lights are designed to be noticeably brighter, at least 2.5 times brighter, as the typical tail, or stop, lights, which often share a filament with an automobile’s turn lights. Despite the increase in brightness, rear-end collisions still seem relatively on the rise. Several possible explanations for this phenomenon have been suggested, including the prevalence of distracted driving to the increased height of drivers’ perception (as vehicles become taller, a driver’s perception of a vehicle’s stop-lights can be impaired). The NHTSA has brought to bear these issues in their commitment to increase third brake light visibility by focusing on increasing third brake light visibility in the upcoming years in response to Congress’ mandate to issue safety standards in 2012.
Even as this latest research into the efficacy of third brake lights is ongoing, the push for greater third-light visibility is already pushing manufacturers to adapt their 2009 and current 2010 model year cars, trucks, vans, and SUVs. This is because there are several provisions of California’s Vehicle Code – that are now being more strictly enforced by police – that regulate the use and condition of third brake lights. California Vehicle Section 24800, for example, states: "No person shall operate any motor vehicle on a highway that is not equipped with at least one working third-brake light located on the rear of the vehicle and that is of a type which has been approved by the department."
FAQs on Third Brake Light Laws
Q: Does the third brake light law apply to all vehicles on California roads?
A: No, there are a number of vehicles that are exempted from the third brake light requirement, including motorcycles, buses with a body width of at least 102 inches and farm trailers. The third brake light requirement does not apply to modular vehicles or trailers, either.
Q: I’m thinking of modifying my vehicle by installing a third brake light for safety. Do I need to submit this modification so it’s legally recognized?
A: No, you don’t have to submit a request for the modification in order to use a third brake light as long as it fits the required standards. The Third Brake Light Modification Request is being phased out. When California began requiring a third brake light in 1986, as part of a test program, vehicle owners were required to submit a Third Brake Light Modification Request form along with their registration renewal . This requirement has been phased out and now all vehicles of 1986 model year or later must be equipped with a third brake light.
Q: If my third brake light burns out, do I have to check it immediately to see if it was just the bulb, or could it be something with the wiring?
A: When a third brake light burns out, or finds another way to stop functioning, it’s up to you, as the owner of the vehicle, to determine what’s broken. Only you know when you’ve had time to inspect whether the lightbulb is burned out or if there’s a problem with the wiring. Your insurance company should cover you for any cost associated with getting the third brake light back in working condition, so long as the lightbulb is the only problem and not something with the wiring or the assembly inside the lens.
