The Federal Motor Carrier Safety Administration on Wednesday gave Aurora Operations — and any other Level 4 autonomous truck fleet that notifies the agency first — a five-year exemption to replace reflective warning triangles with cab-mounted amber beacons. The exemption runs through October 7, 2031, signed by Administrator Derek Barrs.

The decision ends the whiplash of four three-month waivers Aurora has held since October 2025. Kodiak AI, Waabi and Stack AV piled into those waivers along the way.

What does this actually change?

Federal rules still demand that a stopped truck driver place three reflective triangles or six fusees within 10 minutes. A driverless truck has no human to step out and do that. Cab-mounted beacons activate on their own, in five minutes, and keep flashing until the truck moves again or gets recovered.

"Going from a temporary waiver to a five-year exemption gives the industry a lot of confidence," said Jeff Farrah, CEO of the Autonomous Vehicle Industry Association. "As these companies scale, raise money in the capital markets and set up business partnerships, there are often questions about what they are going to do about the warning-triangle issue. Now there is a firm answer."

What the beacons must do

The spec is precise. Amber light, SAE J595 Class 1 photometric output, mounted at least 100 inches off the ground at or above the mirror line. Each truck needs one rearward-facing light on each side of the cab and one forward-facing light. Redundant power — no single-point failure allowed.

FMCSA called the five-minute activation window a "clear, verifiable safety improvement" over the 10 minutes human drivers get.

Where the trucks can run

Operating scope is tight. Trucks stay inside their validated operational design domain. No hazardous materials. No passengers. Doubles cap at two 28-foot trailers. Triples are out. Tankers are fine.

Every carrier other than Aurora must email FMCSA first and swear under penalty of perjury it has the hardware and the discipline. Any crash with beacons on — or that should have been on — gets reported within five calendar days. Annual malfunction reports are due by November 1. States cannot pile on conflicting rules on interstate runs covered by the exemption.

What tipped the agency's view

FMCSA originally denied Aurora and Waymo's joint 2023 request in December 2024. The agency called the original ask too vague — exempting carriers, equipment and vehicles it could not name.

The new exemption names everything. It leaned on data from the narrow waiver Aurora ran from October 10, 2025 through January 9, 2026: 34 trucks, more than 500,000 miles, nearly 10 hours of beacon time, zero reported faults, malfunctions or power issues. FMCSA said the trucks logged no collisions while stopped with beacons on.

Two studies got a closer read. Aurora's October 2022 "Naturalistic Study of Warning Device Equivalency" showed motorists began evasive moves an average of 135.71 meters from beacons versus 133.24 meters from triangles. A Virginia Tech Transportation Institute study prepared for Waymo in August 2022 found beacons pulled earlier braking at night.

Why opponents still aren't buying it

Aurora's application drew 402 comments. OOIDA, the Truck Safety Coalition, Advocates for Highway and Auto Safety and REAL Women in Trucking lined up against. The American Trucking Associations, Waymo, Kodiak AI, Volvo Group North America, Amazon and the National Fraternal Order of Police lined up for it.

Critics worried a jackknifed or angled trailer could hide cab-mounted lights, a single electrical fault could black out the beacons, and 10 hours of planned-stop use was thin evidence for a five-year rule. OOIDA asked FMCSA to wait for its own study of warning devices for stopped trucks.

FMCSA pushed back: terms restrict trucks to their validated ODDs, the agency lacks evidence triangles meaningfully change driver reaction time, and whether any of these devices move the needle on traffic safety remains an unresolved question.

"High-visibility, cab-mounted warning beacons are a critical, 21st-century solution that enhances roadside safety by immediately alerting other road users without ever needing to put a person in harm's way," said Gerardo Interiano, senior vice president of government relations and public affairs at Aurora.

What regulators signaled next

The Autonomous Vehicle Industry Association and Volvo asked FMCSA to extend beacons to traditional trucks too. The agency left that door cracked: updating warning-device requirements for all commercial vehicles, it wrote, "may be ripe for future regulatory action."

Bart Teeter, director of fleet and operational safety at Bot Auto, said the exemption "will give the autonomous freight industry a key piece of regulatory certainty that will allow us to continue to scale safely."

The exemption sticks through October 7, 2031. For AV operators, Farrah said, it opens a deployable pathway in the U.S. — one regulators can refine without restarting the waiver clock every 90 days.