NHTSA Proposes Mandating Cyan Lights for Driverless Vehicles

For years, the industry has debated various methods, from flashing text to audio alerts, for driverless cars to announce their presence, but federal regulators have now proposed a singular visual solution: cyan. The National Highway Traffic Safety Administration (NHTSA) recently released proposed amendments to Federal Motor Vehicle Safety Standard No. 108, aiming to update regulations specifically for autonomous vehicles. This move attempts to balance the reduction of bureaucratic hurdles for human-free designs with the standardization of how robotaxis communicate with their surroundings, primarily through the use of a distinctive blue-green light.

The proposal suggests that manufacturers install cyan-colored marker lamps to clearly and consistently indicate to law enforcement and other road users when an automated driving system is in control. NHTSA argues that cyan fills a specific visual gap because the auto industry already relies on red, amber, white, and flashing blue or red lights for functions like brakes, turn signals, and emergency vehicles. While Mercedes-Benz previously received state-level approval for turquoise lights on its Level 3 Drive Pilot vehicles, the automaker later abandoned the concept in favor of a Level 2++ system. Nevertheless, the agency aims to establish a national standard that operators like Waymo, Nuro, and Zoox, as well as automakers including GM and Mercedes, can adopt uniformly.

Under the draft rules, these cyan lights would remain optional for manufacturers. However, by defining official federal standards for their color, brightness, and placement, NHTSA intends to ensure that any automaker choosing to implement them uses a consistent, legal configuration rather than a confusing array of different colors and signals. The agency is also proposing to eliminate lighting requirements that are illogical for vehicles without human drivers, such as physical hazard switches, manual beam shifters, and internal turn levers.

Additionally, NHTSA is looking to update the 12.8-volt testing standard to allow automakers to design around modern LED architectures without facing excessive administrative burdens. The proposal also considers removing requirements that dictate whether high-beam lights must be positioned above or below low-beam lights. These changes are part of a broader Department of Transportation initiative to streamline the deployment of autonomous vehicles, making it simpler for manufacturers to build cars without traditional controls like steering wheels and pedals that are designed for human operation.

Despite this push for flexibility, regulators are still enforcing existing rules strictly. Last month, NHTSA initiated an audit query into the Tesla Cybercab to examine the process and technical data Tesla used when certifying the vehicle. This inquiry focuses on the absence of certain design features, such as sideview mirrors, pedals, and a steering wheel, all of which are currently required under FMVSS regulations.