The U.S. National Highway Traffic Safety Administration (NHTSA) has proposed new lighting requirements for autonomous vehicles, including the option to use cyan-colored lights to indicate when a vehicle is operating autonomously without a human occupant monitoring the road.
The proposal does not mandate cyan lighting. Instead, it outlines specifications for an optional system intended to provide a consistent visual signal to other road users when an autonomous vehicle is operating in self-driving mode.
The move reflects federal regulators’ efforts to establish a standardized way to identify autonomous vehicles as driverless technology expands across the United States.
Proposed Lighting Would Be Visible From All Sides
Under the proposal, NHTSA suggests that the lights emit cyan, a blue-green color, and remain steadily illuminated rather than flashing. They would be visible from the front, rear and both sides of the vehicle.
The proposal also outlines technical requirements covering the lights’ placement, color and activation. The system would operate when the vehicle is in autonomous mode, rather than simply indicating that automated driving technology is available.
NHTSA has not proposed making the lights compulsory. However, the detailed specifications could help establish a consistent approach for manufacturers that choose to use an external signal to identify autonomous operation.
The proposal would also remove requirements for manually operated controls for turn signals, high-beam headlights and hazard lights, addressing equipment rules that may not align with some emerging autonomous vehicle designs.
Federal Rules Adapt to Driverless Vehicle Designs
The lighting proposal forms part of a wider effort to update U.S. vehicle regulations as autonomous technology develops.
NHTSA Administrator Jonathan Morrison has said the agency is working on a federal framework for automated vehicles while reviewing Federal Motor Vehicle Safety Standards, which govern vehicle safety equipment and design.
Some newer autonomous vehicles depart from conventional automotive layouts. Tesla’s Cybercab and Zoox robotaxi, for example, have designs that do not follow traditional arrangements for driver controls and vehicle equipment, raising questions about how existing requirements should apply.
Federal safety standards were developed largely around vehicles with human drivers, including requirements associated with steering wheels, pedals and mirrors. Updating the rules could help regulators assess newer vehicle configurations while maintaining safety requirements.
Standardized Signals Could Help Road Users
A consistent external signal could help pedestrians, cyclists and other drivers recognize when a vehicle is operating autonomously. However, the proposal’s optional status means that a common visual standard would depend partly on manufacturers choosing to adopt it.
The lighting requirements would address one aspect of autonomous vehicle regulation, rather than establishing a complete framework for driverless deployment. Questions involving vehicle design, operational safety and compliance with existing standards remain part of the broader regulatory effort.
NHTSA’s proposal therefore represents a step toward adapting vehicle equipment rules to autonomous operation, while leaving the use of cyan lights voluntary under the current plan.