NHTSA Proposes Cyan Lights for Driverless Cars

The National Highway Traffic Safety Administration has formally proposed a new federal standard requiring or permitting driverless vehicles to display distinctive cyan-colored lights. This move aims to provide a clear, uniform visual signal to law enforcement and other motorists that a vehicle is currently being operated by an automated driving system rather than a human driver. The agency released these changes as part of a rewrite to Federal Motor Vehicle Safety Standard No. 108, specifically targeting the needs of autonomous vehicles.

The primary objective behind selecting the color cyan is to fill a visual gap in the current automotive lighting spectrum. Existing regulations reserve red, amber, white, and flashing blue or red lights for specific functions such as brake signals, turn indicators, headlights, and emergency vehicle alerts. By introducing a distinct blue-green hue, the NHTSA seeks to ensure that autonomous cars can be identified without confusing road users with signals already associated with human-driven vehicles or emergency services.

There is historical precedent for using similar lighting in the automotive industry. Mercedes-Benz previously received state-level approval for turquoise lights on its Level 3 Drive Pilot vehicles. Although the automaker eventually abandoned that specific approach in favor of a different Level 2++ system, the NHTSA view this as a useful starting point for creating a national standard. The agency intends for this uniform standard to be adopted by major robotaxi operators like Waymo, Nuro, and Zoox, as well as traditional automakers including GM and Mercedes.

Under the proposed rule, the installation of cyan marker lights would remain optional for manufacturers. However, if a company chooses to include them, the new federal standards would dictate the specific color, brightness, and placement. This standardization is designed to prevent a fragmented landscape where different automakers use varying colors and signal patterns, ensuring that any vehicle displaying these lights follows a consistent, legally defined setup.

In addition to the lighting changes, the NHTSA is proposing to eliminate several lighting requirements that are largely irrelevant to vehicles without a human driver. Current regulations mandate the presence of physical hazard switches, manual beam shifters, and turn levers inside the cabin. The agency proposes removing these mandates, recognizing that a fully autonomous vehicle does not require these manual controls. This would allow designers more freedom in crafting the interior space of driverless cars.

The proposal also includes an update to the 12.8-volt testing standard. This change is intended to allow automakers to build around modern LED architectures without facing unnecessary administrative hurdles. Furthermore, the NHTSA is considering removing requirements that dictate the specific vertical positioning of high-beam lights relative to low-beam lights. These adjustments are part of a broader effort to streamline the certification process for vehicles that may lack traditional controls entirely.

This regulatory update fits into a larger Department of Transportation initiative to accelerate the deployment of autonomous vehicles. The federal government is actively working to make it easier for automakers to build cars without traditional human-centric controls, such as steering wheels and pedals. By modernizing these safety standards, regulators hope to remove barriers that have slowed the adoption of fully driverless technology on public roads.

Despite the push for streamlined regulations, the NHTSA remains committed to enforcing existing rules as they are currently written. Last month, the agency opened an audit query into the Tesla Cybercab to examine the technical data and processes Tesla relied upon when certifying the vehicle. The investigation focuses on the absence of certain design features, including sideview mirrors, pedals, and a steering wheel, which are required under the current version of FMVSS. This action demonstrates that while new standards are in development, current compliance remains strictly monitored.

The proposed changes represent a significant step toward defining the visual language of autonomous transportation. By standardizing the use of cyan lights and removing obsolete interior control requirements, the NHTSA aims to create a safer and more predictable environment for the growing number of driverless vehicles expected to enter the fleet. The rulemaking process will now proceed, allowing for public comment before the final standards are established.