The Federal Motor Carrier Safety Administration is granting a National Tank Truck Carriers application for a limited five-year exemption to allow motor carriers operating tank trailers to install a red or amber brake-activated pulsating lamp in the upper center position or in an upper dual outboard position on the rear of the trailers.

These lights will be allowed in addition to the steady-burning brake lamps required by the Federal Motor Carrier Safety. The agency said the exemption would likely achieve a level of safety equivalent to or greater than the level of safety provided by the regulation.

Section 393.25(e) of the FMCSRs requires all exterior lamps to be steady-burning, except turn signal lamps, hazard warning signal lamps, school bus warning lamps, amber warning lamps or flashing warning lamps on tow trucks and commercial motor vehicles transporting oversized loads, and warning lamps on emergency and service vehicles.

NTTC in its application argued that the addition of the brake-activated pulsating lamp will improve safety by improving visibility and prevent accidents.

FMCSA previously granted a similar, but not identical, temporary exemption to one of its member companies, Groendyke Transport. In fact, the Oklahoma-based tank truck carrier said it reduced its rear-end crash rate by more than 30% using this spec.

NTTC cited several studies conducted by the National Highway Traffic Safety Administration on the issues of rear-end crashes, distracted driving, and braking signals. NTTC stated: “Research indicates that there are ways to improve the attention-getting qualities of braking systems. 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.”

The Commercial Vehicle Safety Administration and some other commenters expressed concern that flashing, rotating, or pulsating red lamps are generally permitted only on emergency vehicles. FMCSA responded, however, that those emergency lights are usually high intensity, constantly flashing, rotating or pulsating red lamps visible from all directions on the vehicle and that continuously operate when activated. In contrast, the amber or red brake-activated pulsating lamps requested by NTTC are visible only to the rear of the tanker trailer, and are similar in lamp intensity and flash rate of the vehicle's standard rear hazard warning lamps system currently allowed by the regulations.

And, it said, it couldn’t ignore the results of Groendyke’s experience.

This exemption is applicable Oct., 2020, and ending Oct. 8, 2025.