Flashing Brake Lights – What Are They? Are They Legal? – Car or Motorcycle

Have you encountered a small sports car with blinking brake lights on the highway? The lights flash on and off rapidly when the driver applies the brakes. In this article, I’ll discuss flashing brake lights – what are they? Are they legal?

A car with brake lights that flash on and off could indicate that the driver is applying the brakes heavily. This type of brake technology that BMW first introduced to get the attention of other drivers on the road when the car is making a panic stop.

Different states in the country treat these flashing brake lights differently. For instance, this brake light system in California is legal, just as long as the lights only flash no longer than four times in four seconds. In other states, it is illegal to have this type of brake light.

Read on to learn more about flashing brake lights and if they are legal or not.

Flashing Brake Lights – What Are They?

Flashing Brake Lights

If you see a car with its LED brake lights flashing on and off, it could indicate that the driver is applying the brakes heavily. This technology was first developed and introduced by BMW in the European car market.

It aims to get the attention of other motorists on the road that the driver of the car is heavily applying their brakes. Different states treat this type of braking technology differently in the United States.

For instance, it is perfectly legal to flash your brake lights in California. However, you should only do so four times in four seconds. This means you can only blink your headlights once every second and only for a maximum of four seconds.

In Orlando, Florida, flashing brake lights are treated differently. Steve Montiero, a traffic safety expert, says that if you have brake lights that continuously blink, it could earn you a traffic ticket.

He added that though brake lights are not entirely illegal, they can still confuse drivers on the road. Montiero says it is best to avoid them.

The United Kingdom is more flexible in this matter than the United States. These types of brake lights are not illegal in the British Isles and other European countries.

Overview of Flashing Brake Lights

BMW Developed the Flashing Brake Light Technology

BMW first developed the flashing brake light technology. They designed this type of brake light to get the attention of other drivers on the road that the driver of the car is applying the brakes heavily.

Break Force Distribution or BFD

BMW referred to it as Break Force Distribution or BFD. As time went on, different forms of BFD were developed to cater to different markets. Some considered this technology a step forward in car safety.

Can Be Encoded to the Car’s Engine Control Unit

It can be encoded to the engine control unit of a car, even if the original stock car from the factory does not have it. Cars with this flashing brake light tech are not considered illegal in Europe and the U.K. However, in some U.S. states, it is.

Won’t Fail to Get the Drivers’ Attention

So, this technology is installed in many European cars. Their brake lights can flash if certain conditions are met. This system is designed as a warning to other drivers. As they are very noticeable, the flashing red brake lights won’t fail to get the attention of the drivers at the back.

Prevention of Collisions

An advantage of this system is that possible car collisions will be prevented. The drivers following the car with flashing brake lights will know that the driver of the car in front is having some problems. Other drivers will be able to react accordingly and avoid hitting the car in front.

What Is a DRL Light?

Are Flashing Brake Lights Legal in the U.S.?

Are flashing brake lights legal in the United States? While they may be legal in Europe and the U.K., the United States Department of Transport regulations do not allow the use of flashing brake lights to warn other drivers that a car is doing heavy braking or giving a warning for an emergency stop.

Instead, the USDT allows for brake lights to radiate increased brake light intensity to get the attention of other drivers that the car is doing heavy braking. However, these lights are legal in California, but only if they are not flashing more than four times in four seconds.

Texas

How about Texas? Technically, all kinds of flashing lights are illegal for all passenger and commercial vehicles in this state. They are only allowed on emergency vehicles, such as ambulances, fire trucks, police cars, and rescue vehicles.

Florida

These lighting devices are also illegal in Orlando, Florida. According to Steve Montiero, a traffic safety expert, there are two problems that you can encounter concerning blinking brake lights. First, they blink continuously, and second, they are red.

He says that it is not only distracting to see red flashing continuously on your car. It is illegal as well, he added. The flashing red light can also confuse the other drivers. Most drivers know that brake lights should be solid and not blinking.

They could misunderstand what it means if they see continuous flashing red lights in front of them. There’ll be confusion on the road. Montiero says you could receive a ticket if you have flashing motorcycle brake lights every time you step on the brakes.

Legality and Safety of Using Blue Headlights

Does Flashing Brake Lights Help?

Can Glow an Extra Bright Illumination When Breaking Heavily

Different brake lights are available in the market today and have different purposes. Some brake lights will give the standard illumination when you are slowing down.

Brake lights can glow an extra bright illumination when you do heavy braking. Perhaps your car already has these features.

Stability Control Picks Up the Signal When the Driver Does Heavy Braking

Like other vehicle safety features, such as seat belts, crumple zones, and many others, European car makers were the first to develop emergency stop signals. An example is the stop signal dependent on the car’s stability control feature.

Introduced in the BMW E39 5-Series

If the driver does heavy braking, the stability control will pick up the signal and send it to the lighting control module, which will turn on extra bulbs on the car’s tail lamp. BMW introduced this in the BMW E39 5-Series. They called it the LCM3 Lighting Module.

BMW installed this lighting module in their E46 3-Series compact executive cars and their X5 Mid-Size SUVs. Other European carmakers followed, such as Volvo with its second-generation S80 sedan and Mercedes-Benz with its S-Class executive cars.

How Flashing Brake Light Works

This is basically how this flashing brake light system works:

When the driver steps on the brakes, the brake lamps will light up in two stages. The intensity of the light and the manner of flashing will depend on how sharply the driver steps on the brakes:

1. Normal Braking

The brake lamps and the center brake lamp will turn on.

2. Sharp Braking

The lighted surface of the brake lamps gets bigger. This will happen if the driver does not turn on the rear fog lights.

More About Flashing Brake Light System

flashing brake lights legal

Mercedes-Benz First Offered Flashing Brake Lights

As with any technology, this basic flashing brake light system has undergone many improvements since its inception.

Mercedes-Benz was the first to sell brake lights that flash at 3 to 5 Hz when doing heavy braking at speeds greater than 31 miles per hour. BMW calls this feature “Dynamic Brake Light.”

Legal in Europe

The European Union passed into law that allows the use of flashing brake light systems. So, it is already legal to have it in Europe.

Brake Lights Flashes at 5Hz When the Driver Steps Hard on the Brakes

This system flashes the brake lights at 5Hz when the driver steps hard on the brakes at speeds of around 31 mph. The car’s hazard lights will also turn on if the driver continues their hard braking below nine mph.

The U.S. States Only Allow Steady Burning Brake Lights

However, on the other side of the Atlantic, it is still generally illegal to have flashing brake lights – because of outdated North American lighting standards as dictated by the Federal Motor Vehicle Safety Standards.

The FMVSS 108 section 5.5.10, a governing document for vehicle lighting in the U.S. states, says that all lamps on cars that are not headlamps, hazard warning lamps, turn signals, school bus warning lamps, and side marker lamps “shall be wired to be steady-burning.”

The United States still follows this document despite several studies that show the benefits of using flashing brake lights.

Benefits of Flashing Brake Lights Based on Studies

A study conducted in 2014 revealed that flashing brake lights reduced vehicle collisions by 90.9 percent compared to regular brake lights.

This shows that flashing brake lights can be more effective than automatic emergency braking. The flashing brake light system also does not need a radar sensor to work. With this advantage, it is truly unfortunate that some parts of the U.S. still consider this system illegal.

In several European tests, Mercedes-Benz discovered that drivers reacting to flashing brake lights step on the brakes in 0.4 seconds. This is slightly faster than drivers’ reaction to regular brake lights, which took about 0.6 seconds before they hit the brakes.

Mercedes-Benz Failed to Get the NHTSA’s Permission

In 2005, Mercedes-Benz was unsuccessful in getting the National Highway Traffic Safety Administration (NHTSA) to allow a maximum of 5,000 MBs with flashing emergency stop signals on United States roads.

People Might Mistake the Flashing Brake Lights for Hazard Lamps

Some say that in the United States, some people might mistake the flashing brake lights for hazard lamps or turn indicators. This is not an issue in other parts of the world because they have amber-colored hazards and indicator lamps.

Vehicles with Flashing Brake Lights

All hope is not lost for those who see the value of these flashing brake lights. If you own a late model Mercedes-Benz, a Volkswagen, a BMW, or an Audi, you can code flashing emergency stop signals into your car. That is, if you don’t want to cross the law in your state.

Certain car models manufactured by Volvo and Mercedes-Benz have brake lights that can flash. Their reason for adding this feature is that it creates a visual differentiation between an emergency full stop and slowing down.

Again, is a flashing brake light legal? In California, flashing brake lights are legal according to the Vehicle Code, as long as the lights flash no more than four times within four seconds.

Flashing Brake Lights in the U.K.

It appears that flashing brake lights is legal in the United Kingdom since no specific vehicle lighting regulation prohibits its use. They consider these lights part of what they call ‘Emergency Stop Signal.’

This ESS means a signal to indicate to other drivers at the back of the vehicle that a high delaying force has been applied to the vehicle about the present road conditions.

The law prescribed certain conditions regarding the installation and use of these ESS lights, including:

  • The lamps used should flash in phase at a frequency of 4.0 plus or minus 1.0 Hz.
  • The ESS should operate independently of other lamps.
  • The ESS should be activated and deactivated automatically.
  • The ESS should be activated when the vehicle reaches a speed of 51 kilometers per hour (31 mph).

Frequently Asked Questions

flashing brake lights uk

This controversial topic must have raised some questions in your mind. If you read this section, you might be able to find the answers to your questions:

Are Flashing Brake Lights Legal in the United States?

Generally, it is illegal to have flashing brake lights in many parts of the United States. If you live in California, you are lucky because it is somehow legal to have flashing brake lights in this state.

However, there are some restrictions to this. You can have flashing brake lights as long as the lamps only flash no greater than four times, and it should be within four seconds only.

This means your brake lights should flash only once every second, and the flashing should last only four seconds.

It is illegal to have flashing brake lights in Orlando, Florida, and Texas. Most of the 50 states in the Union also do not allow flashing brake lights. This follows the law prescribed by the FMVSS 108 section 5.5.10.

This governing document for vehicle lighting in the U.S. states that all lamps on cars that are not headlamps, hazard warning lamps, turn signals, school bus warning lamps, and side marker lamps “shall be wired to be steady-burning.”

What Does Flashing Brake Lights Mean?

In Europe, where this brake lighting feature was conceptualized, developed, and first marketed, the meaning is: that the car’s driver is doing heavy braking. Some would call it making a panic stop.

Can I Be Caught If My Brake Lights Are Flashing?

According to a traffic safety officer, if your brake lights continuously flash, you could receive a ticket. Traffic safety officers consider it confusing to other road users to have a car that continuously flashes its red brake lights.

When a driver steps on the brakes, the red brake lights will usually remain solid, not flashing.

Why Are Flashing Brake Lights Legal in the U.K.?

Flashing brake lights are legal in the U.K. and the European Union because they saw their value in reducing car collisions. Unfortunately, the vehicle lighting standards in the U.S. have not kept pace with their European counterparts.

Many European tests were conducted about the usefulness of these flashing brake lights. Mercedes-Benz found out drivers reacting to flashing brake lights stepped on their brakes in 0.4 seconds.

In comparison, drivers who reacted to the standard red brake lights stepped on their brakes in 0.6 seconds. So, drivers react faster to flashing brake lights than conventional brake lights. This small time window can avert potential car crashes.

Additionally, a study conducted in 2014 showed that flashing brake lights reduced vehicle collisions by 90.9 compared to conventional brake lights.

This is just one of the advantages of flashing brake lights. The system of flashing brake lights is not only legal in the U.K. Their law even prescribes it and provides certain parameters of how it should be manufactured and installed on the U.K. manufactured vehicles.

Why Is It Legal in the U.K. and Europe?

It is legal in these parts of the world because they saw the value of the brake light flashing system. These brake lights are sometimes part of a car manufacturer’s original equipment, or O.E. Volvo and Mercedes-Benz are two companies that do this.

They include this system as a safety feature in their cars. The purpose of this system is to create a visual differentiation between an emergency full stop and a slowing down.

In Closing: What are Flashing Brake Lights? Are They Legal?

If you see a car with brake lights that flash rapidly, it could indicate that the driver is heavily applying the brakes on their car. This is a type of brake technology that was developed and introduced by BMW in the European car market.

Its objective is to get the attention of other drivers on the road that the car is breaking heavily.

Different types of treatment for this type of brake light exist in different states. For example, in California, it is legal to have flashing brake lights, just as long as the blinking is not more than four times within four seconds. In many other states, flashing brake lights are entirely illegal.

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