NHTSA Proposes Cyan Marker Lights to Signal When a Robotaxi Is Driving Itself

The National Highway Traffic Safety Administration released proposed amendments to Federal Motor Vehicle Safety Standard (FMVSS) No. 108 on Friday. The proposal would establish a federal specification for cyan marker lamps "to clearly and consistently signal to law enforcement and other road users when an automated driving system is operating the vehicle."

Cyan would be optional for manufacturers. By setting official standards for the light's color, brightness and location, the agency aims to ensure that any automaker choosing to add the lamps uses one consistent, legal setup rather than a mix of colors and signals. Red, amber, white and flashing blue and red are already assigned to brakes, turn signals, headlights and emergency vehicles, leaving blue-green as an unused part of the visual spectrum.

There is some precedent. Mercedes-Benz obtained state-level approval for turquoise lights on its Level 3 Drive Pilot cars, although the automaker has since abandoned the idea in favor of a Level 2++ system, The Verge reported. NHTSA wants a national standard that robotaxi operators such as Waymo, Nuro and Zoox, and automakers including GM and Mercedes, could adopt uniformly.

The proposal also would remove several lighting requirements that serve no purpose in a vehicle without a driver, including physical hazard switches, manual beam shifters and turn levers inside the cabin. NHTSA is further proposing to update the 12.8-volt testing standard so manufacturers can build around modern LED architectures, and is considering dropping requirements that dictate whether high-beam lamps sit above or below low-beam lamps.

The changes are part of a broader Department of Transportation effort to speed the deployment of autonomous vehicles and make it easier to build cars without traditional human controls such as steering wheels and pedals.

Regulators are still enforcing existing standards as written. Last month, NHTSA opened an audit query into the Tesla Cybercab "to examine the process and technical data on which Tesla relied when certifying the Cybercab and related issues," according to The Verge. At issue is the absence of design features such as sideview mirrors, pedals and a steering wheel, all of which are required under FMVSS.