Feds propose cyan lights for driverless cars

The National Highway Traffic Safety Administration has officially proposed that autonomous vehicles use a specific blue-green light to indicate that no human is at the wheel. This latest regulatory move seeks to end years of industry debate over how driverless cars should communicate their status to other road users. The agency is suggesting a shift from a fragmented approach to a unified national standard for vehicle lighting.

The proposal targets Federal Motor Vehicle Safety Standard No. 108. NHTSA aims to rewrite these rules to better accommodate autonomous systems. The goal is to streamline the design process for vehicles that may lack traditional human controls. It also seeks to standardize how these vehicles signal their operational state to the surrounding traffic.

Regulators specifically suggest cyan-colored marker lamps for this purpose. The agency believes this color would clearly and consistently signal when an automated driving system is in control. This signal is intended for both law enforcement officers and other drivers. Choosing cyan allows the industry to utilize a color that is currently underrepresented in standard automotive lighting.

The selection of this specific hue addresses a gap in current visual conventions. The auto industry already relies on red, amber, white, and flashing blue or red lights. These colors are reserved for brake lights, turn signals, headlights, and emergency vehicles. Cyan offers a distinct visual option that could theoretically avoid confusion without clashing with existing traffic signals.

There is some historical precedent for using similar colors in autonomous contexts. Mercedes-Benz previously received state-level approval for turquoise lights on its Level 3 Drive Pilot vehicles. However, the automaker has since moved away from that concept in favor of a Level 2++ system. Despite this shift, NHTSA wants to establish a uniform national standard that all major players can adopt.

The proposed rule would make cyan marker lights optional for manufacturers. However, if a company chooses to install them, the federal standards would dictate the color, brightness, and location. This ensures that any automaker using the feature provides a consistent and legal setup. It prevents a confusing mix of different colors and signals from different companies.

NHTSA is also proposing to eliminate several lighting requirements that may not apply to driverless vehicles. Current rules demand physical hazard switches, manual beam shifters, and turn levers inside the car. The agency suggests removing these mandates to allow for cleaner interior designs. It also plans to update the 12.8-volt testing standard to support modern LED architectures without excessive administrative hurdles.

This update fits into a broader Department of Transportation push to streamline the deployment of autonomous vehicles. The government aims to make it easier for automakers to build cars without traditional controls like steering wheels and pedals. These components are designed for human operation but may be unnecessary in fully autonomous models. The agency is also considering removing requirements about the specific placement of high-beam versus low-beam lights.

Despite the push for streamlined regulations, regulators are still enforcing 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 issue centers on the absence of required design features such as sideview mirrors, pedals, and a steering wheel. These elements are currently mandated under FMVSS, highlighting the tension between new proposals and current enforcement.

The proposal represents a significant step in defining the visual language of autonomous driving. By standardizing the use of cyan lights, NHTSA hopes to reduce uncertainty for both drivers and passengers. It also provides a clear framework for companies like Waymo, Nuro, and Zoox to follow. The final rule will depend on the outcome of the comment period and subsequent regulatory review.