NHTSA Proposes Cyan Lights to Identify Self-Driving Cars

Federal regulators are seeking a unified method to identify autonomous vehicles operating without a human behind the wheel, proposing a specific exterior light color to signal that an automated driving system is in control. The proposal aims to resolve years of debate over how to visually distinguish driverless cars from those operated by people.

The National Highway Traffic Safety Administration (NHTSA) has released proposed changes to Federal Motor Vehicle Safety Standard (FMVSS) No. 108 to establish a national standard for autonomous vehicles. The agency's proposal would mandate cyan-colored marker lamps to signal to law enforcement and other road users that an automated driving system is operating the vehicle. The choice of cyan is intended to avoid confusion with existing colors used for braking, turn signals, headlights, and emergency vehicles. A precedent for such lights was established when Mercedes-Benz received state-level approval for turquoise lights on its Level 3 Drive Pilot cars, though the company has since discontinued that system. NHTSA aims to create a uniform standard that all autonomous vehicle operators and automakers can adopt.

Under the proposed rule, these cyan marker lights would be optional for manufacturers. However, by creating federal standards for their color, brightness, and location, NHTSA aims to ensure that any automaker who chooses to add them uses a consistent and legal setup, preventing a confusing array of different colors and signals. In addition to the lighting proposal, NHTSA is also seeking to eliminate requirements for physical hazard switches, manual beam shifters, and turn levers in vehicles without a human driver. The agency is also updating testing standards for LED light architectures and considering the removal of rules dictating the placement of high-beam lights relative to low-beam lights.

This regulatory update aligns with the Department of Transportation's broader effort to streamline the deployment of autonomous vehicles and facilitate the creation of cars without traditional controls like steering wheels and pedals. While regulators work to simplify rules for driverless cars, they are also actively enforcing existing standards. Last month, NHTSA opened an audit query into the Tesla Cybercab to examine the process and technical data used to certify the vehicle, focusing on the absence of required design features such as sideview mirrors, pedals, and a steering wheel.

The proposal to standardize cyan lights for autonomous vehicles is part of a larger push to adapt federal safety standards for a future with self-driving technology. The agency is working to remove outdated requirements that do not apply to vehicles without a human driver while creating clear, consistent signals for identifying when an automated driving system is in operation. This effort to streamline regulations for autonomous vehicles is a key part of the Department of Transportation's goal to facilitate the deployment of this technology.