Federal Proposal Sets 1 Color for Self-Driving Car Signals

Federal regulators have issued a specific proposal to standardize the visual signaling of driverless cars, designating a single cyan hue as the primary indicator that an automated system is in control. The National Highway Traffic Safety Administration, or NHTSA, released these changes as part of a broader update to Federal Motor Vehicle Safety Standard 108. This move aims to replace the current patchwork of regional rules and manufacturer-specific designs with a uniform national framework for autonomous vehicles.

The core of the proposal requires that any vehicle using an automated driving system display distinct blue-green marker lamps. The agency states this color choice is intended to clearly and consistently signal to law enforcement and other road users that a human is not at the wheel. By selecting cyan, NHTSA seeks to fill a visual gap in the existing traffic language. Currently, the automotive industry relies on red for brakes, amber for turn signals, white for headlights, and flashing blue or red for emergency vehicles. A new color avoids potential confusion with these established cues.

This standardization effort builds on limited state-level precedents. Mercedes-Benz previously obtained approval for turquoise lights on its Level 3 Drive Pilot vehicles. However, the automaker later abandoned that specific hardware approach in favor of a different system level. NHTSA now intends to create a federal baseline that operators such as Waymo, Nuro, and Zoox, as well as manufacturers like General Motors and Mercedes, can adopt uniformly across the country.

Under the proposed rules, the installation of cyan marker lights would remain optional for manufacturers. The agency is not mandating that every self-driving car feature the lights. Instead, the proposal establishes official federal standards for the color, brightness, and location of these lamps. This approach ensures that if a manufacturer chooses to include the feature, the setup is legally consistent and recognizable to all road users, preventing a chaotic mix of different colors and signals.

The update also targets outdated requirements that do not apply to vehicles without human drivers. Current regulations often demand physical controls such as hazard switches, manual beam shifters, and turn levers. NHTSA proposes removing these requirements to accommodate designs that may lack traditional cabin interfaces. Additionally, the agency is looking to update the 12.8-volt testing standard. This change would allow automakers to build around modern LED architectures without facing unnecessary administrative hurdles.

Further simplification is included in the proposal regarding high-beam and low-beam light placement. The agency is considering removing requirements that dictate whether high-beam lights must sit above or below low-beam lights. This flexibility is part of a wider administrative push by the Department of Transportation to streamline the deployment of autonomous vehicles. The goal is to make it easier for companies to build cars that may eventually lack traditional controls like steering wheels and pedals, which are primarily designed for human operation.

Despite the move toward streamlined regulations, regulators are still strictly enforcing existing rules. Last month, NHTSA opened an audit query into the Tesla Cybercab. The agency is examining the technical data and processes Tesla relied on when certifying the vehicle. The audit focuses on the absence of certain design features, including sideview mirrors, pedals, and a steering wheel. These elements are currently required under the existing FMVSS framework, highlighting the ongoing tension between traditional safety standards and emerging autonomous vehicle technology.

The proposed changes represent a significant step in defining how autonomous vehicles will communicate with the public. By setting a clear visual standard, the federal government aims to reduce uncertainty on the road. This initiative is part of a larger effort to integrate driverless technology into the national transportation infrastructure while maintaining safety through consistent, recognizable signals.