NHTSA proposes cyan marker lamps for cars driven by automation

NHTSA proposes cyan marker lamps for cars driven by automation

26 October 2026: The US National Highway Traffic Safety Administration wants to let carmakers fit cyan "ADS marker lamps" that show when an automated driving system is in control, and to stop applying turn signal, hazard and beam switch rules written for human drivers to vehicles that have no steering wheel or pedals. The proposal to amend Federal Motor Vehicle Safety Standard No. 108, the US lighting standard, was published in the Federal Register on 26 October, and comments close on 25 November 2026.

Not yet independently verified. We read the proposal in the Government Publishing Office text of the Federal Register; NHTSA has not posted a press release on it. This is a proposal, and the final rule may differ. We will update this when it can be confirmed, and remove this note.

For companies building robotaxis, driverless shuttles and the software that runs them, it is one of the first concrete edits to the federal safety standards for vehicles designed without manual controls. NHTSA notes that such vehicles "currently are not available for consumer purchase", but that some manufacturers and rideshare operators already run them in a number of US cities.

A lamp that tells the street who is driving

The marker lamps would be optional. NHTSA is not proposing that every ADS vehicle carry one, only that any lamp a manufacturer chooses to fit must meet the new requirements, and that the lamp may not appear on a vehicle without ADS functionality. The draft specification is detailed:

• Colour: cyan, the blue-green defined in SAE J578, because amber, red and white already carry fixed meanings
• Pattern: steady burning when the system is engaged; NHTSA asks for research-based comment on flashing the lamps to signal intended movement to pedestrians
• Number and placement: one or two lamps on each of the front, sides and rear, so four to eight in all, mounted at least 15 inches high, inside or outside the vehicle
• Brightness: two sets of minimum intensities, one with headlamps off and one with headlamps on, with front and rear minimums of 0.3 cd and 0.05 cd respectively

The draft follows SAE Standard J3134, first issued in May 2019 and revised in December 2025 to add rear and side lamps, and it departs from it in places. NHTSA would not allow the front lamps to be optically combined with daytime running lamps, as a 2023 UNECE draft would, because it concluded the mix would shift the perceived colour.

Who asked for it

The notice cites a survey of more than 4,400 drivers in the United Kingdom, Japan, the United States and Germany, presented to the UNECE lighting working party in April 2025, in which upwards of 80 percent of US and UK respondents said ADS vehicles should carry a marker lamp. It also records that Mercedes-Benz pressed for 360-degree visibility of cyan lamps and ran a two-year on-road validation in California from 2023 to 2025 with five vehicles. The American Association of Motor Vehicle Administrators recommends the lamps so police can tell whether a car is being driven by its system or by a person.

Internationally the picture is unsettled. UNECE's automated vehicles working party recommends uniform provisions for such a signal but does not recommend requiring additional lighting yet, citing the need for more research.

Rules written for drivers, removed for vehicles without one

The other changes strip requirements that assume a human at the wheel. For vehicles with an ADS and no manually operated driving controls, the self-cancelling and manual-control requirements for turn signal, hazard warning and beam switching would no longer apply, and some telltale requirements would be narrowed in the same way. References to a driver would be removed from the definition of the hazard warning signal operating unit. NHTSA stresses that any vehicle that does have manual controls, with or without an ADS, must still meet every existing requirement.

Two changes reach ordinary cars too. Integral beam headlamps, which now dominate the market, would be tested at the power they are designed for rather than at a fixed 12.8 volts, and the rule that the lower beam must sit above the upper beam in vertical arrangements would go.

Timing and the docket

Comments go to docket NHTSA-2026-1519 on regulations.gov. Because every change adds flexibility rather than a new burden, NHTSA says a final rule should take effect immediately, with no lead time. Our automotive software category lists 20 companies. The next step is the comment deadline on 25 November.

Related on TrustList:

• Wayve signs production deal to put its AI Driver in Mercedes-Benz cars
• Bolt picks NVIDIA software for robotaxis, starting in Madrid in 2027
• Volvo Cars adopts NVIDIA Hyperion as NVIDIA adds a safety evidence framework

Sources

• Federal Register: Federal Motor Vehicle Safety Standards; Modernization of FMVSS No. 108 To Accommodate ADS-Equipped Vehicles (document 2026-21794), 26 October 2026
• GovInfo: Federal Register volume 91, number 205, pages 67243 to 67261, full text, 26 October 2026