FMCSA grants brake-activated pulsating light exemption for tanker trucks

The Federal Motor Carrier Safety Administration granted a waiver to the National Tank Truck Carriers to allow fleets to install a red or amber brake-activated pulsating light (lamp in the upper center position or in an upper dual outboard position on the back of tanker trailers. In addition to the steady-burning brake lamps required by the Federal Motor Carrier Safety Regulations.

This exemption is applicable through Oct.  8, 2025.

Groendyke Transport, of Enid OK, recently was granted a limited five-year exemption to allow use of an amber brake-activated pulsating lamp on its trailers in addition to the steady-burning brake lamps required by the Federal Motor Carrier Safety Regulations (FMCSR).

FMCSA granted a similar exemption to tanker fleet Groendyke Transport in April 2019. It allows carriers to install an amber brake-activated pulsating light in the upper center on the back of tanker trailers in addition to the steady-burning brake lights. Groendyke said over a 30-month period, using the lights reduced rear-end collisions by nearly 34% and eliminated all rear crashes at railroad crossings.

Peterson supplied amber pulsating brake light
 amber light which features a built-in pulsating effect.

“This exemption is a simple, common-sense way to reduce accidents in our industry,” said NTTC in a statement. “When Groendyke installed these lights on their trailers and petitioned FMCSA, all rear-end collisions dropped by 33.7%.”

In its petition, NTTC cited several studies conducted by the National Highway Traffic Safety Administration (NHTSA), another agency in the U.S. Department of Transportation, on the problems of rear-end crashes, distracted driving, and braking signals.

“Research indicates that there are ways to improve the attention-getting qualities of braking systems,” NTTC stated. “Including a pulsating brake lamp on a lead vehicle has quantifiable effect on the drivers of following vehicles and measurably reduces rear-end collisions. Drivers are redirected and altered faster and more efficiently when a pulsating brake lamp draws their attention to the lead vehicle. As a result, rear-end collisions can be prevented or at least reduced.”


§393.25e says that exterior lamps need to be steady burning when in use, with exceptions including:

  • Turn signal lamps
  • Hazard signal lamps
  • School bus warning lamps
  • Amber warning lamps on tow trucks
  • Amber warning lamps for trucks hauling oversized loads
  • Warning lamps for emergency vehicles

This regulation exemption is an addition, rather than a subtraction, which is to say tanker trucks will still need to have the commonly-known steady-burning red brake lights at the rear end in addition to pulsating amber brake lights.


The exemption is effective as of October 8th, 2020, and will last five years until October 8th, 2025. When that time comes, the FMCSA will consider whether to expand the exemption further. Giving more time and perhaps applying it to more types of commercial vehicles, or may scrap the entire prospect if the results do not match what Groendyke Transport and the NHTSA found in their studies.

The way things look now, though, this change seems to be for the better. It appears an easy way for tanker trucking companies to reduce collisions by a little over 33%, and if the contents of the tanker prove to be volatile, the lower the risk of catastrophe, the better.

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