The Third Brake Light: A Safety Law's Evolution

The third brake light, or Center High Mounted Stop Lamp (CHMSL), became law in the United States in 1986 for new cars, and in 1994 for light trucks. The CHMSL is an inexpensive safety feature that warns following drivers to slow down, reducing the number of rear-end collisions and saving lives, property, and money.

The third brake light became law in 1986 for new cars

The third brake light, or Center High Mounted Stop Lamp (CHMSL), became law in 1986 for new cars. This means that since 1986, all new cars have been required to have three brake lights instead of the traditional two. By the mid-1990s, nearly every car on the road featured this third brake light system.

The third brake light was invented to enhance road safety. In 1974, psychologist John Voevodsky conducted a study on taxi cabs in San Francisco to determine whether a third brake light would prevent rear-end collisions. The study found that taxis with a third brake light had 60% fewer rear-end collisions than those without. This led to larger studies by the National Highway Traffic Safety Administration (NHTSA), which consistently showed that the third brake light reduced collisions.

As a result of these findings, the NHTSA began requiring all new cars to have a third brake light in 1986. This was extended to all new light trucks in 1994. The NHTSA estimated that once all cars on the road had high-mounted brake lights, there would be 900,000 fewer rear-end accidents per year, 40,000 fewer injuries, and a $434 million reduction in property damage costs for consumers.

The third brake light is located in the centre of the car, usually on the rear of the rear seat back, and is designed to be in the line of vision of the driver in the car behind. When the driver steps on the brake pedal, the third brake light illuminates to inform other drivers that the vehicle is slowing down or stopping. This simple, low-cost addition to vehicles has made a significant impact on road safety and has helped to prevent countless accidents.

In 1994, it became law for light trucks

The third brake light is an important safety feature that has been shown to reduce accidents and injuries. The idea for the third brake light can be traced back to the 1970s when psychologist John Voevodsky conducted a study on taxi cabs in San Francisco. Voevodsky's study found that cabs equipped with a third brake light had 60% fewer rear-end collisions than those without one.

Following Voevodsky's study, the National Highway Traffic Safety Administration (NHTSA) took an interest in improving brake light regulations in the United States. The NHTSA's own large-scale studies confirmed Voevodsky's findings, leading to the 1986 and 1994 laws requiring all new cars and light trucks, respectively, to have a third brake light.

The third brake light is a relatively inexpensive addition to vehicles, costing an estimated $4 to $7 per car. Once all cars on the road had high-mounted brake lights, the NHTSA estimated that there would be 900,000 fewer rear-end accidents per year, resulting in 40,000 fewer injuries and a $434 million reduction in property damage costs.

Today, third brake lights have evolved to include better illumination and advanced features, such as the pulsing third brake light, which helps to prevent accidents caused by distracted drivers.

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

The third brake light, which came into law in the US in 1986 for cars and 1994 for light trucks, is also known as the Center High Mounted Stop Lamp (CHMSL). This extra light, mounted in the base of the rear windshield, warns following drivers to slow down when the brakes are applied.

The story of the third brake light can be traced back to the mid-1970s and a study by psychologist John Voevodsky. He was curious about whether a third brake light would prevent rear-end collisions. Voevodsky's hypothesis was proven correct when he installed an extra light in the rear window of 343 taxi cabs in San Francisco, and found that taxis with a third brake light had 60% fewer rear-end collisions than those without.

Following Voevodsky's study, the National Highway Traffic Safety Administration (NHTSA) took an interest in improving brake light regulations in the United States. By the mid-1990s, nearly every car on the road featured the three-brake light system.

The CHMSL is an important safety feature, and a non-functioning one is a violation of the law. It is also an effective way of reducing the chance of a rear-end crash. The NHTSA estimates that once all cars on the road have high-mounted brake lights, there will be 900,000 fewer rear-end accidents a year, 40,000 fewer injuries, and a $434-million cut in property damage costs for consumers.

The third brake light has evolved to include better illumination and advanced features. For example, the pulsing third brake light helps prevent distracted drivers and keep all motorists safe as they travel.

A non-functioning CHMSL is a violation of the law

The Center High Mounted Stop Lamp (CHMSL) is a proven safety feature that has been required on all new cars since 1986 and light trucks since 1994. This third brake light, mounted in the centre of the vehicle at eye level, provides an extra signal to following drivers that the vehicle is slowing down or stopping. Its implementation followed a study by psychologist John Voevodsky, who in 1974, equipped 343 San Francisco taxicabs with a third brake light, finding that those taxis had 60% fewer rear-end collisions than a control group.

The CHMSL is a mandated safety feature and a non-functioning light is a violation of the law. The specific laws regarding brake lights vary across different locations, but in most places, a non-functioning CHMSL will result in a fine and/or a requirement to fix the light. For example, in Washington State, a non-functioning CHMSL can be grounds for a police officer to pull a driver over and issue a citation.

The importance of the CHMSL cannot be understated, as it significantly reduces the risk of accidents, injuries, and property damage. It is estimated that once all cars on the road had the CHMSL installed, there would be 900,000 fewer rear-end accidents per year, 40,000 fewer injuries, and a reduction in property damage costs of $434 million.

In addition to the safety benefits, the CHMSL is also a relatively low-cost feature to implement, with an estimated cost of only $4 to $7 per car. This makes it an extremely cost-effective way to improve road safety and reduce the number of accidents and injuries.

While some may argue that other safety features, such as airbags, are more important in preventing serious injuries and fatalities, the CHMSL plays a crucial role in preventing rear-end collisions, which can cause significant property damage and injuries, even at relatively low speeds. Therefore, it is essential for vehicle owners to ensure their CHMSL is functioning properly, not only to comply with the law but more importantly, to help keep themselves and others safe on the road.

The third brake light was invented by psychologist John Voevodsky

The third brake light, now a standard feature on all modern vehicles, was invented by psychologist John Voevodsky. In the mid-1970s, Voevodsky conducted a study to determine whether adding a third brake light would improve safety and prevent rear-end collisions. The study took place in San Francisco, with 343 taxis equipped with the third brake light and 160 taxis serving as a control group. The results of the 10-month experiment were significant: taxis with the third brake light had 60.6% fewer rear-end collisions, and injuries to drivers and repairs to taxis were also reduced.

Voevodsky's study made a compelling case for the addition of a third brake light. Following his findings, the National Highway Traffic Safety Administration (NHTSA) conducted its own larger-scale experiment, which further supported the idea that a third brake light reduced accidents and injuries. As a direct result of these studies, the NHTSA mandated that all new cars be equipped with a third brake light starting in 1986. This requirement was extended to all new light trucks in 1994.

John Voevodsky's innovative idea and rigorous research had a profound impact on automotive safety. By questioning the status quo and seeking to improve safety standards, Voevodsky's work not only influenced industry regulations but also helped save lives and reduce property damage. His study is a testament to the power of scientific inquiry and its potential to bring about positive change.

The evolution of the third brake light continued beyond its initial implementation. Over time, advancements were made to improve illumination and introduce new features. One notable development is the pulsing third brake light, which has proven to be effective in reducing accidents caused by distracted drivers. This innovation highlights the ongoing efforts of automakers to enhance the safety and performance of vehicles.

Today, the third brake light is an essential safety feature, mandated by law and relied upon by drivers worldwide. Its history, rooted in psychological research, exemplifies the intersection of science and real-world applications, showcasing how innovative ideas can lead to significant advancements in everyday life.

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