NHTSA proposes national standard for cyan robotaxi lights

The National Highway Traffic Safety Administration is proposing that driverless vehicles use a specific blue-green color to indicate when an automated system is in control. This single hue, known as cyan, is intended to replace the fragmented approaches currently used by different manufacturers and operators. The agency released these proposed changes to Federal Motor Vehicle Safety Standard No. 108, which governs lighting and electrical systems in vehicles.

The primary goal is to create a uniform signal that law enforcement and other road users can easily recognize. Currently, the automotive industry relies on red, amber, white, and flashing blue or red lights for functions like braking, turning, and emergency services. NHTSA argues that cyan fills a visual gap without causing confusion with these existing signals. The proposal states that these marker lamps should clearly signal when an automated driving system is operating the vehicle.

The move follows years of debate over how driverless cars should communicate their status to the public. Previous ideas included flashing text, audio alerts, and various custom lighting schemes. By setting a national standard, the federal government aims to provide a consistent framework for major players in the sector. This includes robotaxi operators such as Waymo, Nuro, and Zoox, as well as traditional automakers like General Motors and Mercedes-Benz.

While the use of cyan lights would remain optional for manufacturers, the proposal establishes strict guidelines for their implementation. NHTSA intends to define the exact color, brightness, and location of these lamps. This ensures that if a company chooses to install them, the setup is legally consistent across the country rather than a confusing mix of different designs. The agency noted that Mercedes-Benz previously received state-level approval for turquoise lights on its Level 3 Drive Pilot vehicles, although the company later shifted toward a Level 2++ system.

In addition to adding new lighting standards, the proposal seeks to remove outdated requirements that do not apply to vehicles without human drivers. Current rules mandate physical hazard switches, manual beam shifters, and turn levers inside the cabin. NHTSA proposes eliminating these demands to accommodate designs that may lack traditional controls. The agency is also updating the 12.8-volt testing standard to allow automakers to utilize modern LED architectures without facing unnecessary administrative hurdles.

Further simplifications include reconsidering the current rules that dictate whether high-beam lights must be positioned above or below low-beam lights. These changes are part of a broader effort by the Department of Transportation to streamline the deployment of autonomous vehicles. The government aims to make it easier for manufacturers to build cars that do not require traditional human-operated controls like steering wheels and pedals.

Despite these efforts to modernize regulations, regulators continue to enforce existing rules strictly. Last month, NHTSA opened an audit query regarding the Tesla Cybercab. The agency is examining the technical data Tesla used to certify the vehicle. The audit focuses on the absence of certain design features, such as sideview mirrors, pedals, and a steering wheel, which are currently required under FMVSS standards.

This regulatory update highlights the tension between modernizing safety standards for new technology and maintaining current legal frameworks. As autonomous vehicles become more common, the need for clear, standardized communication methods between these machines and human drivers will likely increase. The proposed cyan light serves as a foundational step in establishing that visual language nationwide.