Federal Draft Sets One Color for Robotaxis

A fundamental question in the autonomous vehicle industry has a new proposed answer. The National Highway Traffic Safety Administration (NHTSA) has suggested a single visual signal to identify when a car is operating without a human driver. That signal is a specific shade of blue-green known as cyan.

The agency released proposed amendments to Federal Motor Vehicle Safety Standard No. 108, which governs vehicle lighting. The rule change targets autonomous vehicles and serves two purposes. It reduces regulatory burdens for designs that lack a human operator and it creates a uniform method for robotaxis to communicate with their surroundings. According to NHTSA, the cyan lamps would clearly signal to law enforcement and other road users when an automated driving system is active.

Regulators chose cyan because the automotive industry already uses red, amber, white, and flashing blue or red lights for standard functions like braking and turn signals. Cyan fills a visual gap without creating confusion. While Mercedes-Benz previously received state-level approval for turquoise lights on its Level 3 Drive Pilot, the company has since shifted to a Level 2++ system. NHTSA aims to create a national standard that companies like Waymo, Nuro, Zoox, GM, and Mercedes can all adopt in the same way.

The proposed cyan lights would remain optional for manufacturers. However, if a company chooses to install them, it must follow federal requirements for color, brightness, and placement. This prevents a patchwork of different colors and signals from emerging across the industry.

The proposal also removes lighting requirements that are unnecessary for vehicles without human drivers. Current rules mandate physical hazard switches, manual beam shifters, and turn levers inside the cabin. NHTSA would eliminate these controls. The agency also plans to update the 12.8-volt testing standard to accommodate modern LED systems and is considering removing rules about the vertical placement of high-beam lights relative to low-beam lights.

These changes support a wider Department of Transportation effort to accelerate the deployment of autonomous vehicles. The goal is to make it easier for automakers to build cars without traditional controls like steering wheels and pedals. The move simplifies the design process for vehicles intended for driverless operation.

Existing rules remain in force until the new standard is finalized. Last month, NHTSA opened an audit query into the Tesla Cybercab. The review examines the technical data Tesla used to certify the vehicle. The focus is on the absence of design features required by current federal standards, including sideview mirrors, pedals, and a steering wheel.