NHTSA Proposes Optional Cyan Lights for Autonomous Vehicles

The National Highway Traffic Safety Administration (NHTSA) proposed a draft regulation on Friday to use cyan-colored lights to identify autonomous vehicles. The agency is updating Federal Motor Vehicle Safety Standard No. 108 to create a national standard for these optional marker lamps, which would signal automated driving systems to law enforcement and other road users.

Cyan lights would be optional for manufacturers but standardized in color, brightness, and placement. The proposal aims to fill a visual gap without conflicting with existing red, amber, white, or emergency vehicle lighting. "In a draft proposal released Friday, it suggested a whole new color for vehicle lamps, cyan, to signal autonomous operation," NHTSA said.

Lighting Requirements and Visibility Standards

The proposed cyan lights must activate only when the vehicle operates autonomously and deactivate when a driver is actively controlling the vehicle. They must be visible from all angles, with markers on the front, sides, and rear positioned at least 15 inches off the ground.

The lights should turn on and off simultaneously and remain visible at all times during autonomous operation. This separate visual niche is designed to avoid misleading other people using the road.

Industry Context and Previous Attempts

This is not the first attempt to establish a visual identifier for automated vehicles. Mercedes-Benz previously received state-level approval for turquoise lights on its Level 3 Drive Pilot cars. The company first proposed the cyan lighting concept alongside that system and trialed it in California for two years before later abandoning the idea.

Globally, China has announced a similar regulation using turquoise lights with an optional 2028 effective date.

Regulatory Scope and Manufacturer Flexibility

The broader regulatory update to FMVSS No. 108 is designed to allow flexibility for autonomous vehicle design while standardizing light specifications. Installation of the cyan lights remains voluntary for manufacturers. The NHTSA wants to define federal requirements for the color, brightness, and placement of the lights, though specific details are not yet provided.

The proposal supports simplifying the deployment of autonomous vehicles without traditional controls. It includes eliminating some lighting requirements that do not make sense for vehicles without a human driver. These proposed changes would remove mandates for physical hazard switches, manual beam shifters, and turn levers inside driverless vehicles.

NHTSA is also considering dropping rules specifying high beam positioning relative to low beams. The regulation applies specifically to vehicles operating autonomously, not when a driver is actively driving. The proposal will be open for public comment for 30 days under docket NHTSA-2026-1519.