Autonomous Vehicle Standards: Cyan Lights Proposed

The National Highway Traffic Safety Administration has officially proposed a distinct visual cue for driverless vehicles. The agency wants robotaxis to display cyan-colored marker lamps to signal that an automated driving system is in control. This move ends a long period of uncertainty regarding how autonomous cars should visually communicate their status to other road users. The new guidance offers a single, standardized color choice for the industry.

For years, the debate over how to identify driverless cars has involved various concepts, including flashing text and audio alerts. Regulators have now settled on a specific hue to fill a gap in the current lighting spectrum. Red, amber, white, and flashing blue or red lights are already reserved for functions like braking, turning, and emergency vehicles. Cyan is intended to be easily distinguishable from these existing signals, preventing confusion among drivers and law enforcement officers.

This proposal is part of a broader revision to Federal Motor Vehicle Safety Standard No. 108. The update aims to tailor federal rules specifically for autonomous technology. It seeks to remove administrative hurdles that were designed for traditional human-operated cars. By standardizing the color, brightness, and location of these lights, NHTSA hopes to create a uniform national standard. This would allow operators like Waymo, Nuro, and Zoox, as well as automakers such as GM and Mercedes, to adopt consistent designs.

The idea is not entirely new. Mercedes-Benz previously received state-level approval for turquoise lights on its Level 3 Drive Pilot vehicles. Although the automaker later shifted to a different system, the precedent supports the federal push for a unified approach. Under the new draft rule, cyan marker lights would remain optional for manufacturers. However, if a company chooses to use them, they must adhere to the official federal specifications. This prevents a confusing patchwork of different colors and signal patterns across the country.

The proposal also simplifies existing requirements that do not apply to vehicles without human drivers. Current rules mandate physical controls such as hazard switches, manual beam shifters, and turn levers. NHTSA suggests removing these mandates to allow for more flexible interior designs. The agency is also updating the 12.8-volt testing standard to accommodate modern LED lighting architectures. Additionally, it is considering dropping the requirement that dictates whether high-beam lights must sit above or below low-beam lights.

This regulatory shift aligns with the Department of Transportation’s broader goal of streamlining the deployment of autonomous vehicles. The administration wants to make it easier for manufacturers to build cars that lack traditional controls like steering wheels and pedals. These features are often unnecessary for fully autonomous models. By clarifying the rules, the government aims to reduce the friction between innovation and compliance.

Despite the forward-looking proposal, regulators are still applying existing rules strictly. Last month, NHTSA opened an audit query into the Tesla Cybercab. The investigation examines the technical data Tesla used to certify the vehicle. The focus is on the absence of certain design features, including sideview mirrors, pedals, and a steering wheel. These elements are currently required under FMVSS regulations.

The next steps involve public review and potential adjustments to the proposed rule. Automakers and industry groups will have the opportunity to respond to the draft before it becomes final. If adopted, the cyan light standard will provide a clear legal framework for the next generation of driverless transportation. It marks a significant step toward integrating autonomous vehicles into the broader traffic ecosystem.