Driverless Car Lighting: Federal Blue-Green Standard Proposed

For everyday drivers in New York and New Jersey, the look of the cars passing you on the highway may soon change. Federal regulators are proposing that driverless vehicles display a distinct blue-green light to indicate that no human is behind the wheel. This visual cue is designed to help other road users, including police officers, quickly recognize when an automated system is in control. The goal is to create a consistent signal that cuts through the current ambiguity of how self-driving cars communicate their status to the surrounding traffic.

The push for a standardized light follows years of debate over the best way to alert the public to the presence of autonomous vehicles. Previous discussions included ideas like flashing text, audio alerts, or custom lighting patterns, but the National Highway Traffic Safety Administration (NHTSA) has settled on a specific color. The agency is rewriting Federal Motor Vehicle Safety Standard No. 108 to accommodate these new vehicles. By choosing cyan, regulators are filling a visual gap. The auto industry already uses red for brakes, amber for turn signals, white for headlights, and flashing blue or red for emergency vehicles. A blue-green hue offers a clear distinction without confusing existing traffic patterns.

There is some history behind this specific color choice. Mercedes-Benz previously received state-level approval to use turquoise lights on its Level 3 Drive Pilot cars, although the company later shifted its strategy toward a Level 2++ system. Despite that shift, NHTSA wants to establish a national standard. This would allow operators like Waymo, Nuro, and Zoox, as well as automakers such as GM and Mercedes, to adopt a uniform setup. If the proposal moves forward, the federal government will define the exact color, brightness, and placement of these marker lamps to ensure consistency across different manufacturers.

Under the current proposal, installing these cyan lights would be optional for manufacturers. However, if a company decides to add them, they must follow the official federal standards. This prevents a fragmented situation where different companies use different colors or intensities, which could confuse drivers. The rule aims to simplify the design process by removing requirements that do not make sense for a vehicle without a human driver. For example, current rules mandate physical hazard switches, manual beam shifters, and turn levers. NHTSA is proposing to drop these requirements, along with specific rules about the placement of high-beam and low-beam lights.

The agency is also updating the 12.8-volt testing standard. This change would allow automakers to build around modern LED architectures without dealing with unnecessary administrative hurdles. This update is part of a broader effort by the Department of Transportation to streamline the deployment of autonomous vehicles. The administration wants to make it easier to build cars that lack traditional controls like steering wheels and pedals, which are primarily intended for human operation.

While the proposal aims to simplify things, regulators are still enforcing existing 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 certain design features, such as sideview mirrors, pedals, and a steering wheel, which are currently required under federal safety standards. This audit highlights the ongoing tension between the push for new autonomous designs and the existing regulatory framework.