Feds want robotaxis to signal ‘I’m driving’ with cyan-colored lights

Federal regulators are seeking to mandate a blue-green light for self-driving cars to indicate when human drivers are not present behind the wheel. After extensive deliberation on how automated vehicles should communicate their lack of human control, the National Highway Traffic Safety Administration (NHTSA) has adopted a singular solution: cyan lights.

The proposed changes to Federal Motor Vehicle Safety Standard (FMVSS) No. 108 aim to streamline regulations for autonomous vehicles and establish uniform signaling for robotaxis. A mix of red, amber, white, and flashing blue/red lights are typically used for functions such as brakes, turn signals, headlights, and emergency vehicles.

NHTSA believes that cyan could serve as a visual gap filler without causing confusion for road users. Mercedes-Benz had previously obtained state-level approval for turquoise lights on its Level 3 Drive Pilot cars, although the company later abandoned the plan in favor of a Level 2++ system. The proposed rule allows manufacturers to incorporate cyan marker lights voluntarily, but NHTSA seeks to standardize their color, brightness, and placement to avoid confusion among road users.

Current regulations require physical hazard switches, manual beam shifters, and turn levers in human-driven vehicles, but NHTSA is proposing to eliminate these requirements for autonomous cars. Additionally, the agency is updating the 12.8-volt testing standard to accommodate modern LED technology. NHTSA is also considering removing requirements regarding the positioning of high-beam lights.

This update is part of the Department of Transportation's broader initiative to facilitate the deployment of vehicles without traditional controls, such as steering wheels and pedals. However, regulators have not yet abandoned the rules as written. Last month, NHTSA launched an audit inquiry into Tesla's Cybercab to scrutinize the company's certification process and related issues, primarily due to the absence of certain design features like sideview mirrors, pedals, and steering wheels, which are mandated under FMVSS.