NHTSA proposes optional cyan lights for driverless cars and rewrites lighting rules for vehicles like the Cybercab

The US National Highway Traffic Safety Administration (NHTSA) has proposed changes to the federal lighting standard so that it fits cars with no steering wheel or pedals. The proposal also creates an official, optional signal for self-driving cars: cyan marker lamps. The document went on public inspection on October 23 and is scheduled for publication in the Federal Register on Monday, October 26, followed by a 30-day comment period.

Tesla is not named, but the Cybercab is exactly the kind of vehicle the rule is written for.

Cyan lamps: what NHTSA proposes

The lamps would be optional. But a carmaker that fits them would have to follow one common design:

• Four to eight lamps: one or two each at the front, on each side and at the rear, with at least one visible from every direction.
• At least 15 inches (about 38 cm) above the ground.
• Steady, not flashing. NHTSA asks for comments on whether flashing should be allowed for signalling.
• Colour: the blue-green cyan defined in the SAE J578 standard, which looks different from the blue used by police.
• Meaning: the lamps would only be on when the car is driving itself with no expectation that a person inside is monitoring the road.

NHTSA points to an updated SAE standard, work at the United Nations, and input from Mercedes-Benz, which told the agency it tested cyan lamps on five vehicles in California between 2023 and 2025. California already allows such lamps under state law.

Rules written for drivers, rewritten for software

The second part of the proposal deals with requirements that assume a human driver. Today, turn signals on most passenger cars must cancel themselves when the steering wheel turns back and must be cancellable by hand. The high-beam switch must work with a simple hand or foot movement. Dashboard warning lights must show when the indicators or high beams are on.

Under the new wording, those rules would only apply to vehicles with 'manually operated driving controls'. A driverless car would still need turn signals, hazard lights and a way to switch beams, but that could be done by the computer. The word 'driver' would disappear from the definition of the hazard warning switch. NHTSA's reasoning is simple: an automated system cannot forget that its indicator is on, so a self-cancelling mechanism adds no safety.

NHTSA calls the proposal deregulatory and expects no extra costs. It also includes two changes for ordinary cars: integral beam headlamps would be tested at their marked voltage rather than a fixed 12.8 volts, and low beams would no longer have to sit above high beams in vertical layouts.

What it means for Tesla and the Cybercab

The Cybercab has no steering wheel, pedals or mirrors. Tesla says it meets federal safety standards as built and does not need an exemption. That matters, because exemptions are capped at 2,500 vehicles a year per manufacturer. NHTSA is checking Tesla's claim and has given the company until October 30 to provide sworn answers on how it certified the car.

A rule like this would remove some of the grey areas in the lighting standard for vehicles like the Cybercab. NHTSA itself says that without such updates, makers of driverless cars would probably keep asking for exemptions. The proposal follows earlier 2026 plans to update rules on gear selection, wipers, defrosting and tyre information for cars without manual controls.

Why it matters

Cyan lights would give police, pedestrians and other drivers a quick, consistent way to tell that nobody is driving. Because the lamps are optional, it is not yet clear whether Tesla would use them.

What to watch next

Comments will be open for 30 days after publication. After that, NHTSA can finalise, change or drop the rule. In the short term, the bigger date for Tesla is October 30, when its Cybercab answers are due.