Feds Propose Cyan Lights for Driverless Cars

The National Highway Traffic Safety Administration is proposing a specific visual identifier for autonomous vehicles: a cyan-colored light. This single hue has emerged as the federal answer to a years-long debate over how driverless cars should communicate their status to the public. The agency is seeking to rewrite Federal Motor Vehicle Safety Standard No. 108 to accommodate vehicles that no longer require human operators behind the wheel.

The core of the proposal centers on the use of cyan marker lamps. Regulators argue this color is distinct enough to signal when an automated driving system is in control without causing confusion among other road users. Currently, the automotive industry relies on red, amber, white, and flashing blue or red lights for functions like braking, turn signals, headlights, and emergency services. Cyan fills a visual gap, offering a clear indicator that separates robotaxis from traditional traffic and law enforcement vehicles.

This standardization effort builds on existing industry experiments. Mercedes-Benz previously received state-level approval for turquoise lights on its Level 3 Drive Pilot vehicles. Although the automaker later abandoned that specific Level 3 approach in favor of a Level 2++ system, the precedent supports the need for a uniform national standard. NHTSA intends for this rule to apply broadly to major players in the space, including robotaxi operators like Waymo, Nuro, and Zoox, as well as automakers such as GM and Mercedes.

Under the new rules, cyan marker lights would remain optional for manufacturers rather than mandatory. However, the proposal establishes official federal standards for the light's color, brightness, and placement. This ensures that any automaker choosing to adopt the feature does so with a consistent and legally compliant setup, preventing a fragmented market where different companies use varying colors or signal patterns.

The agency is also proposing to remove several lighting requirements that are impractical for vehicles without human drivers. Current regulations mandate physical hazard switches, manual beam shifters, and turn levers inside the cabin. NHTSA seeks to eliminate these mandates, allowing for cleaner, more automated interior designs. Additionally, the proposal updates the 12.8-volt testing standard to accommodate modern LED architectures, reducing administrative hurdles for manufacturers. The agency is also considering removing rules that dictate whether high-beam lights must be positioned above or below low-beam lights.

This regulatory update is part of a broader Department of Transportation initiative to streamline the deployment of autonomous vehicles. The goal is to make it easier for automakers to build cars without traditional controls like steering wheels and pedals, which are designed for human operation. By simplifying these requirements, the government aims to accelerate the integration of driverless technology into the mainstream automotive landscape.

Despite these efforts to modernize standards, regulators continue to enforce existing rules strictly. Last month, NHTSA opened an audit query into the Tesla Cybercab. The agency is examining the technical data and processes Tesla used to certify the vehicle. The primary concern involves the absence of specific design features, such as sideview mirrors, pedals, and a steering wheel, all of which are currently required under Federal Motor Vehicle Safety Standards.

The stakes are high as the industry moves toward a future with fewer human drivers. A clear, standardized signal like the cyan light could significantly enhance safety and public understanding of autonomous operations. By aligning federal regulations with technological advancements, NHTSA aims to create a clearer path for the widespread adoption of robotaxis across the United States.