Federal Rules Now Point to Cyan Lights for Driverless Cars

The federal government has settled on a specific color to tell the world when a car is driving itself. The National Highway Traffic Safety Administration is proposing that driverless vehicles use cyan marker lamps to signal that an automated system is in control. This decision ends a long period of uncertainty about how these vehicles should communicate with the rest of the traffic. It provides a single, standardized visual cue for everyone on the road.

The proposal targets Federal Motor Vehicle Safety Standard No. 108. NHTSA is rewriting the rules to fit the reality of autonomous vehicles. The agency wants to streamline regulations while standardizing how these cars interact with their environment. The core of the plan is the use of a distinctive blue-green light. This color is chosen because it is not currently used for other standard vehicle functions. Red, amber, white, and flashing blue lights are already assigned to brakes, turn signals, headlights, and emergency vehicles. Cyan fills the visual gap without creating confusion for human drivers.

There is some history behind this choice. Mercedes-Benz previously received state-level approval for turquoise lights on its Level 3 Drive Pilot cars. Although the automaker later moved in a different direction with a Level 2++ system, the precedent remains. NHTSA aims to create a national standard that can be adopted by major players. This includes robotaxi operators like Waymo, Nuro, and Zoox, as well as automakers such as GM and Mercedes. A uniform approach prevents a confusing mix of different colors and signals across the country.

Under the new rules, these cyan lights would be optional for manufacturers. However, the agency is setting strict guidelines for their color, brightness, and location. If a company chooses to install them, the setup must be consistent and legal. This ensures that a cyan light on one robotaxi means the same thing as a cyan light on another. It removes the guesswork for other drivers and law enforcement officers who need to quickly identify an automated vehicle.

The proposal also removes several lighting requirements that do not make sense for cars without human drivers. Current rules require physical hazard switches, manual beam shifters, and turn levers inside the vehicle. NHTSA is proposing to drop these mandates. The agency is also updating the 12.8-volt testing standard. This change allows automakers to build around modern LED architectures without dealing with outdated administrative hurdles. Additionally, the agency is considering eliminating rules that dictate the physical placement of high-beam lights relative to low-beam lights.

This update is part of a broader push by the Department of Transportation. The goal is to make it easier to deploy autonomous vehicles. Regulators want to simplify the process for building cars that lack traditional controls like steering wheels and pedals. These components are designed for human operation and are often unnecessary in a fully automated system. By streamlining these rules, the government hopes to accelerate the adoption of driverless technology on public roads.

However, regulators are still enforcing current rules strictly. Last month, NHTSA opened an audit query into the Tesla Cybercab. The agency is examining the technical data Tesla used to certify the vehicle. The main issue is the absence of design features such as sideview mirrors, pedals, and a steering wheel. These elements are currently required under existing safety standards. This ongoing review highlights the tension between updating rules for the future and enforcing them in the present.