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Truck brake-light exemption denied despite industry support

FMCSA worries pulsing lights could distract motorists

An application from a company specializing in pulsating brake lights for trucks has been denied by federal regulators despite strong support from the trucking industry.

Fayetteville, Arkansas-based Intellistop Inc., which makes a device that prompts preexisting brake lights to pulse briefly for added safety when brakes are engaged (see video, below), had sought an industrywide exemption from federal regulations that require all commercial vehicles be equipped with steady-burning brake lamps.

Intellistop’s exemption application, filed in 2020, had been supported by the American Trucking Associations, the Arkansas Trucking Association, Werner Enterprises and several other carriers and individuals.

But the Federal Motor Carrier Safety Administration ruled that a major bar it uses to grant such exemptions — evidence that it would achieve a level of safety equivalent to or greater than would be achieved absent the exemption — had not been cleared.

“While the agency recognizes the existing data that supports the potential safety value of alternative rear-signaling systems in general, it is also mindful of the data deficiencies in this area,” FMCSA stated in a notice to be published in the Federal Register on Friday.

“Data deficiencies include the effect on nearby drivers if many vehicles on a roadway are equipped with pulsing brake lights and whether such lighting would serve to improve driver attention or, alternatively, cause confusion or distraction.”

Intellistop demonstration video. Source: Intellistop

FMCSA also noted that Intellistop’s exemption request contrasts with previous exemption applications it approved that apply to auxiliary lamps for individual companies and organizations. Intellistop’s exemption, by comparison, would alter the functioning of required lamps and would apply to all commercial vehicles.

“FMCSA is required to monitor implementation of the exemption to ensure compliance with its terms and conditions and ensure that operation under the exemption meets and maintains an equivalent level of safety,” the agency stated. “Because of the broad scope of Intellistop’s application, FMCSA would not be able to sufficiently monitor operations under the exemption.”

Intellistop’s application was not unopposed: An influential dissenter was the Commercial Vehicle Safety Alliance (CVSA).

CVSA acknowledged data supporting the safety benefits of amber brake-activated pulsing lamps, but it opposed equipping trucks with pulsing red lamps because they are typically associated with emergency vehicles.

“Allowing red pulsating lamps on the rear of commercial motor vehicles may negatively impact the driving public’s recognition and response to emergency vehicles,” CVSA stated. “Further, many states have laws prohibiting nonemergency vehicles from having pulsating red lights. If the exemption allows for the installation of red pulsating lights, it would be in direct conflict with state laws in several states.”

The Transportation Safety Equipment Institute (TSEI), which lobbies for standardization of vehicle safety equipment, also urged FMCSA to deny the application.  

“The requirement that stop lamps … be steady burning is longstanding,” TSEI stated. “We do not believe FMCSA should make the leap from pulsating brake-activated warning or auxiliary lamps to pulsating required lamps without a thorough consideration of safety data and research … to ensure consistency across all vehicles equipped with such lamps.”

Click for more FreightWaves articles by John Gallagher.


  1. Allan Purl

    As a whole, US vehicle code lags far behind Europe when it comes to features that significantly improve safety.

    Headlight and brake light modulators have been available for motorcycles as an aftermarket add-on since AT LEAST 1995 or 96. As a motorcycle rider, I am aware that modulators have improved the safety of motorcyclists by helping people to recognize the presence of the motorcycle and that it is stopping.

    As technology available in vehicles (and our hands) has changed, drivers on the roads have an increasing number of distractions competing with the task of safely operating a motor vehicle for their attention.

    Those who say the flashing lights would diminish response to emergency vehicles seem to miss one tiny, yet significant, detail. Flashing lights always attract attention more quickly than a steady burning one.

    When it comes to avoiding collisions, early recognition of a hazard is most paramount to safety. The sooner one recognizes and reacts to a hazard, the better the chances of avoiding an accident. This is why some road hazard warning systems include flashing lights.

    Just as the small size of motorcycles works against them when it comes to perception and risk assessment and avoidance, the large size of CMV’s also works against them for the same reason. Their large size tends to take away from the perception of their movements and just how close they may be.

  2. Kenneth Adams

    They should be outlawed on everything. First time behind one tonight never got close enough to see what kind of car. Dark and raining, these lights are nothing but a distraction.

  3. PC McGee

    This is a recipe for disaster and I am happy it was rejected. The last thing we need is to turn a busy highway into a sea of flashing red lights, especially at night.

  4. G. Booth

    It’s not up to the vehicle having additional features on the rear to warn following driver’s. It’s by law the responsibility of the following driver’s to pay attention and maintain a safe following distance.

  5. Paul W

    I’m baffled. If ever the was a no brainer- this is it! Common sense would tell you the new system would make a safety difference, but when has common sense been a strong point of a government agency? Sounds like they want to spend more of our tax dollars to study it to death. Also, I believe this rule has been changed in Europe; isn’t that a good precedence? As for the CVSA, the red blinking lights are on top of emergency vehicles, not at the bottom where trucks brake light are located. Stupid reason! The TSEI believe it’s always been done this way, so it shouldn’t be changed. Seriously? You sound like a cranky grandpa!

  6. Big guy

    compression deceleration and regenerative braking need to be addressed first. Perhaps those performance vehicles need pulsing amber lights. Amber lights were thought well of because they reduced a driver’s stress level when assessing speed of vehicles perhaps as far as ten lengths ahead.

  7. David Lastoria

    so many of today’s drivers drive in a daze, and/or are distracted and do not realize simple things like brake lights being on. I applaud Intellistop for their product, and will be installing these on my vehicles. Motorcycles have them. A few cars have them. trucks should as well.

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John Gallagher

Based in Washington, D.C., John specializes in regulation and legislation affecting all sectors of freight transportation. He has covered rail, trucking and maritime issues since 1993 for a variety of publications based in the U.S. and the U.K. John began business reporting in 1993 at Broadcasting & Cable Magazine. He graduated from Florida State University majoring in English and business.