NHTSA Proposes Mandatory Cyan Lights to Identify Robotaxis on U.S. Roads

Federal regulators have moved to establish a uniform visual signal for autonomous vehicles. The National Highway Traffic Safety Administration (NHTSA) released proposed amendments to Federal Motor Vehicle Safety Standard No. 108. The rule change targets the growing fleet of driverless cars operating in American cities.

The proposal designates a specific blue-green color, known as cyan, for marker lamps. NHTSA states these lights would clearly signal to law enforcement and other road users when an automated driving system is active. The agency selected cyan because the auto industry already uses red, amber, white, and flashing blue or red lights for braking, turn signals, and emergency functions. This choice avoids visual confusion on the road.

The rewrite of the lighting standard serves two primary goals. First, it creates a national standard for companies like Waymo, Nuro, and Zoox, as well as automakers including GM and Mercedes-Benz. Second, it removes regulatory burdens for vehicles designed without human drivers. Currently, these manufacturers must navigate a patchwork of state-level approvals and varying design signals.

Under the new proposal, cyan lights would remain optional for manufacturers. However, if a company chooses to install them, the federal rules would dictate the color, brightness, and placement. This ensures any robotaxis on the road use a consistent and legal configuration. The move follows earlier state-level approvals, such as those granted to Mercedes-Benz for turquoise lights on its Level 3 Drive Pilot vehicles, which the company later dropped in favor of a different system.

NHTSA also plans to scrap lighting requirements that rely on human operation. The agency proposes removing rules that require physical hazard switches, manual beam shifters, and turn levers inside the vehicle. It will update the 12.8-volt testing standard to accommodate modern LED systems. Additionally, the agency is considering dropping rules regarding the vertical placement of high-beam lights relative to low-beam lights.

These changes align with a broader Department of Transportation push to accelerate the deployment of autonomous vehicles. The government aims to simplify the process for building cars without traditional controls like steering wheels and pedals. While regulators are updating the rules for future vehicles, they continue to enforce existing standards for current models.

Last month, NHTSA opened an audit query into the Tesla Cybercab. The agency is examining the technical data Tesla relied on when certifying the vehicle. The focus of the review includes the absence of sideview mirrors, pedals, and a steering wheel, all features required under the current federal standards.