DOT Clears the Road for Driverless Vehicles

The National Highway Traffic Safety Administration has proposed allowing cyan-colored exterior lights on vehicles operating with automated driving systems, giving nearby motorists a consistent visual signal that a vehicle may be operating without a human driver.

NHTSA proposes cyan lighting standard

In a notice of proposed rulemaking published in the Federal Register, NHTSA outlined proposed updates to Federal Motor Vehicle Safety Standard No. 108, which governs vehicle lighting and reflective equipment.

The proposal would create a new category of steadily illuminated cyan lamps for vehicles operating under an automated driving system. The lights would be intended to distinguish automated vehicles from conventional vehicles using the existing red, amber and white lighting configurations.

NHTSA said the proposed changes would modernize requirements developed when vehicle operation was based on the assumption that a human driver was always in control. The revisions also would account for newer LED lighting technology and vehicles that may not include traditional manual controls.

Uniform signal could apply across state lines

A nationwide cyan-light standard would provide a consistent signal for motorists, pedestrians and other road users encountering an automated vehicle. Supporters of the proposal say a uniform requirement could reduce confusion and avoid different visual indicators being used in different states.

The issue has become more significant as companies develop vehicles capable of operating with reduced or no human input. Level 4 automated vehicles, for example, are designed to handle all driving tasks within specific operating conditions, although the technology may be limited to designated areas or routes.

Some proposed or developing automated vehicle designs do not include a steering wheel or pedals. Existing federal vehicle standards were largely written for vehicles with conventional manual controls, creating regulatory challenges for companies seeking to deploy those designs commercially.

Autonomous trucking adds urgency to debate

The proposed lighting changes come as automated trucking operations and testing continue to expand. Volvo Autonomous Solutions and Waabi recently launched a commercial autonomous trucking operation involving freight moves on the Dallas-to-Houston corridor for logistics provider Warp.

Other companies, including Kodiak AI and Charger Logistics, are also pursuing autonomous freight operations. The Federal Motor Carrier Safety Administration has granted an exemption involving driverless trucks, while NHTSA’s proposal addresses broader vehicle design and lighting requirements.

If finalized, the rule would establish a federal framework for identifying automated vehicles through exterior lighting. The proposal remains subject to the federal rulemaking process, including review and public input, before any requirements take effect.