The Evolution Of Brake Light Laws: Third Light Mandates

The third brake light, or Center High Mount Stop Lamp (CHMSL), has been a legal requirement in the United States since 1986 for passenger cars and 1994 for light trucks. The Reagan administration mandated the CHMSL to reduce the number of rear-end collisions and injuries by improving the braking signal recognition of following drivers. The CHMSL is placed higher than the two typical brake lights, capturing the line of sight of the drivers following the car. While it is unclear whether the mandate has met its goal, the consensus is that the third-light mandate has worked, with studies showing a reduction in rear-end crashes.

The third brake light was mandated by law in 1986 for passenger cars

The third brake light, or Center High Mount Stop Lamp (CHMSL), was mandated by law in 1986 for passenger cars in the United States. This law was issued by the Reagan Administration, requiring all cars to be outfitted with high-mounted brake lamps, or a third brake light.

The Center High Mounted Stop Lamps mandate was aimed at significantly reducing the number of rear-end collisions and injuries by improving the braking signal recognition of following drivers. The third brake light is placed higher and more prominently at the back of the car, capturing the line of sight of the drivers following the vehicle. This makes the braking reaction faster and helps prevent accidents.

The National Highway Traffic Safety Administration (NHTSA) estimated that the third brake light regulation would result in 900,000 fewer crashes, 40,000 fewer injuries, and a $434 million reduction in property damage costs annually for consumers. The cost of implementing this safety feature was estimated to be between $4 to $7 per car.

The third brake light law was generally accepted by auto manufacturers as a low-cost way to improve safety. While it is unclear if the mandate met the expected mark, experts agree that the third-light mandate worked and improved safety on the roads.

The third brake light became law for light trucks in 1994

The third brake light, or Center High Mount Stop Lamp (CHMSL), became a legal requirement for light trucks in 1994. This was eight years after the Reagan administration mandated that all cars be outfitted with high-mounted brake lamps, starting with 1986 models.

The third brake light is placed higher than the two typical brake lights below, capturing the line of sight of drivers following the vehicle. This makes the braking reaction faster and helps to prevent rear-end collisions.

Federal law mandates that all vehicles have the third brake light, and it must be comparable to the other brake lights to avoid distracting drivers behind the vehicle. The third brake light law was based on effective tests done with taxi cabs and company fleet vehicles, which showed a reduction in rear-end crashes with the use of the extra light.

The third brake light is placed higher than the two typical brake lights

The third brake light, also known as the Center High Mount Stop Lamp (CHMSL), is placed higher than the two typical brake lights to capture the line of sight of drivers following the vehicle. This placement ensures that the braking reaction of the driver behind is faster, as the third brake light is more prominent and visible.

The CHMSL is typically centred and placed above the two standard brake lights, which flank the vehicle. This positioning ensures that the third brake light is within the direct line of sight of the driver behind, reducing the likelihood of it being obscured by other vehicles on the road. The height of the CHMSL is regulated and standardised, ensuring that it is mounted at an optimal height relative to the conventional left and right brake lights.

The placement of the CHMSL is designed to prevent rear-end collisions and improve road safety. By placing the third brake light higher, it serves as a more immediate and noticeable signal to the driver behind, allowing them to react more quickly and effectively. This is especially crucial in situations where the vehicle ahead brakes suddenly or in cases of low visibility.

The effectiveness of the CHMSL in reducing rear-end collisions has been supported by various studies and real-world data. Tests conducted with taxi cabs and company fleet vehicles demonstrated a significant reduction in rear-end crashes when the third brake light was installed. This led to the mandate of the CHMSL in passenger cars starting with 1986 models, followed by light trucks in 1994.

The addition of the third brake light is a relatively low-cost modification that offers significant benefits in terms of safety. While it may not be a lifesaver in high-speed accidents, it is particularly effective in preventing low-speed collisions that often result in property damage and injuries.

The third brake light is mandated by federal law

The third brake light, also known as the Center High Mount Stop Lamp (CHMSL), is mandated by federal law in the United States. This law, which came into effect in 1986 for passenger cars and in 1994 for light trucks, requires all vehicles to have a third brake light installed within the car.

The CHMSL is typically placed higher and more centrally than the two standard brake lights, allowing it to capture the line of sight of drivers following the vehicle. This placement improves braking reaction time and helps to prevent rear-end collisions. The third brake light is also required to be comparable in appearance to the other brake lights to avoid distracting other drivers.

The mandate for the CHMSL was issued by the Reagan Administration and was generally accepted by automakers as a low-cost way to improve safety. While it is challenging to determine the exact impact of the third brake light law, estimates from the National Highway Traffic Safety Administration (NHTSA) predicted that it would result in 900,000 fewer crashes, 40,000 fewer injuries, and a significant reduction in property damage costs annually.

It is important to note that covering or removing the CHMSL is considered a violation of the law, and failure to comply with this regulation may result in legal consequences.

The third brake light is also known as the Center High Mount Stop Lamp (CHMSL)

The CHMSL is generally required to illuminate steadily and not permitted to flash. On passenger cars, the CHMSL may be placed above the back glass, affixed to the vehicle's interior just inside the back glass, or integrated into the vehicle's deck lid or into a spoiler. Trucks, vans, and commercial vehicles sometimes have the CHMSL mounted to the trailing edge of the vehicle's roof. The CHMSL is required by regulations worldwide to be centred laterally on the vehicle. The height of the CHMSL is also regulated, both in absolute terms and with respect to the mounting height of the vehicle's conventional left and right stop lights.

The CHMSL may use one or more filament bulbs or LEDs, or a strip of neon tubing as its light source. The use of LEDs in the CHMSL offers several advantages, including a very long service life, extreme vibration resistance, high colour durability, and high efficiency.

The third brake light law went into effect in 1986 for passenger cars in the US, and light trucks in 1994. The decision was based on effective tests done with taxi cabs and company fleet vehicles, illustrating a reduction in rear-end crashes with the use of the extra light.

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