Federal proposal mandates cyan lights for autonomous vehicles

Federal regulators have proposed a specific color code for driverless vehicles: cyan. The National Highway Traffic Safety Administration (NHTSA) released a draft rule requiring autonomous cars to use distinct blue-green marker lamps. This light serves as a clear signal to law enforcement and other drivers that no human is at the wheel.

The agency is rewriting Federal Motor Vehicle Safety Standard No. 108 to accommodate autonomous technology. The proposal aims to create a uniform national standard for how robotaxis communicate with the surrounding traffic environment. Instead of a patchwork of different signals, all compliant vehicles would use the same visual cue.

Cyan was selected because it fills a visual gap in current automotive lighting. Red, amber, white, and flashing blue or red lights are already assigned to specific functions like brakes, turn signals, and emergency services. A blue-green hue avoids confusion with these existing colors while remaining distinct to the eye.

This move follows earlier experiments with similar technology. Mercedes-Benz previously received state-level approval for turquoise lights on its Level 3 Drive Pilot vehicles. Although the automaker later pivoted to a Level 2++ system, the precedent supports the idea of using non-standard colors to indicate automation levels.

Under the new proposal, cyan marker lights would remain optional for manufacturers. However, if a company chooses to include them, the federal standard would dictate the exact color, brightness, and location on the vehicle. This ensures consistency across different brands and prevents a confusing mix of custom designs.

NHTSA is also proposing to remove outdated requirements that do not apply to vehicles without human drivers.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. The agency suggests eliminating these requirements to allow for cleaner, more modern interior designs.

The update also addresses technical testing standards. The proposal seeks to modernize the 12.8-volt testing rules to accommodate current LED architectures. This change is designed to reduce administrative hurdles for automakers building vehicles with advanced lighting systems.

Additionally, the agency is considering removing rules that dictate the vertical placement of high-beam and low-beam lights. These specific positioning requirements are seen as less relevant for vehicles that rely on automated systems rather than human visual cues for operation.

This regulatory update is part of a broader effort by the Department of Transportation to streamline the deployment of autonomous vehicles. The goal is to make it easier for automakers to build cars that may lack traditional controls like steering wheels and pedals, which are primarily designed for human operation.

Despite these efforts to simplify regulations, enforcement remains strict. Last month, NHTSA opened an audit query into the Tesla Cybercab. The review examines the technical data and certification process Tesla used for the vehicle. The investigation focuses on the absence of certain design features, such as sideview mirrors, pedals, and a steering wheel, which are currently required under existing safety standards.

Industry players including Waymo, Nuro, and Zoox, along with automakers like GM and Mercedes, are expected to monitor the proposal closely. A unified standard could accelerate the adoption of driverless technology by providing clear guidelines for manufacturers and operators. The final rule will determine how these lights are integrated into the next generation of autonomous fleets.