Watch Now

Warning devices for stopped trucks to go by wayside?

Waymo, Aurora seek exemption to replace signs and road flares with cab-mounted beacons

Warning equipment placed on the road is required under current regulations. (Photo: Jim Allen/FreightWaves)

WASHINGTON — Two self-driving truck companies have told regulators their technology for warning motorists of a truck stopped on the side of the highway is safe enough to replace traditional reflective signs and road flares.

Waymo LLC and Aurora Operations Inc. have asked the Federal Motor Carrier Safety Administration to exempt for five years their highly automated (Level 4 and Level 5) trucks from regulations requiring such roadside warning devices. If FMCSA approves the exemption, the companies would be allowed to use cab-mounted beacons instead.

“Waymo and Aurora believe it is possible to achieve the safety purpose of the warning device in an alternative way by using forward- and rearward-facing amber flashing lights mounted on the cab at a height above the upper edge of the sideview mirrors,” FMCSA stated in a notice to be posted in the Federal Register on Friday.

“Waymo and Aurora each separately tested variants of such devices and have concluded that the use of the cab-mounted warning devices was equally or more effective in enabling road users to recognize and react to the potential hazard presented by the stopped [truck].”

Specifically, the companies are seeking an exemption from two regulations related to roadside warning equipment: the types of devices allowed and where they are placed.

When a truck comes to a stop on a highway or shoulder for any cause other than necessary traffic stops, regulations require drivers use either three emergency reflective triangles or three to six road flares, depending on the type, as a warning to other drivers.

Regulations also require the devices be placed in three locations within 10 minutes:

  • On the traffic side, four paces (about 10 feet) from the vehicle, in the direction of approaching traffic.
  • In the center of the traffic lane or shoulder, 40 paces (about 100 feet) from the vehicle, in the direction of approaching traffic.
  • In the center of the traffic lane or shoulder, 40 paces (about 100 feet) from the vehicle, in the direction away from approaching traffic.

In addition, if the truck is stopped within 500 feet of a curve, crest of a hill or other obstruction, the warning device is required to be placed up to 500 feet away from the truck.

Because the cab-mounted devices for which the companies seek an exemption are flashing lamps, Waymo and Aurora also want an exemption from a requirement that exterior lamps be steady-burning.

“All exterior lamps (both required lamps and any additional lamps) shall be steady-burning with the exception of 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 authorized by state or local authorities,” the regulation states.

While FMCSA’s notice does not make clear that the exemption, if granted, would extend beyond Waymo and Aurora, an FMCSA spokesperson verified that the relief requested “was not limited” to just the two companies.

Emily Warren, head of public policy for Embark, a competitor, confirmed that her company was consulted by Waymo and Aurora when they were crafting their application.

“Favorable action from FMCSA would create safer work environments for human truck drivers, while paving a path for the commercialization of AV trucking technology,” Warren told FreightWaves in a statement.

“We hope to see federal policymakers take swift action on this decision, enabling the entire industry to utilize this important safety innovation.”

Exemptions from regulations that apply to truck safety equipment have been growing as autonomous vehicle (AV) technology advances and more carriers begin installing products tech companies assert will lead to less crashes and fatalities. Safety advocates contend, however, such exemptions can also be risky.

“Granting individual five-year exemptions is arbitrary, sets an unsafe precedent for other AV companies to receive similar treatment and allows roadway users across the nation to unwittingly be used as lab test participants without consent,” Zach Cahalan, executive director of the Truck Safety Coalition, told FreightWaves.

“FMCSA needs to exhibit leadership by completing its ongoing rulemaking on the safe integration of ADS driving systems that set clear, well-thought-out safety standards that apply to all AV trucking companies, such as requiring a human driver during Level 4 and 5 testing.”

Comments on the exemption are due April 3.

Click for more FreightWaves articles by John Gallagher.


  1. Larry Nickles

    Larry. Just worked an accident as a Firefighter and CDL holder. I have a drivers video where the no safety equipment was displayed including flashers. The design of the feed trailer that was struck would have not allowed the cab beacon to be seen. Real bad idea just like driverless trucks.

Comments are closed.

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.