WASHINGTON — Tesla’s newly deployed Cybercab robotaxi has come under federal scrutiny in the United States after the country’s top vehicle safety regulator opened an investigation into how the driverless vehicle was certified for road use.

The National Highway Traffic Safety Administration (NHTSA) launched an Audit Query examining Tesla’s certification that the Cybercab complies with applicable Federal Motor Vehicle Safety Standards. The investigation came immediately after Tesla began commercial deployment of the vehicle in Austin, Texas.

Investigation Focuses on Tesla’s Certification

The federal inquiry is designed to examine the technical information and procedures Tesla relied upon when certifying the Cybercab.

Unlike conventional passenger vehicles, the Cybercab was designed without a steering wheel, accelerator pedal or brake pedal. It also lacks traditional exterior mirrors, features that are incorporated into many existing federal vehicle-safety requirements.

NHTSA said it wants to determine whether Tesla’s interpretation of existing regulations properly supports its certification decisions.

Cybercab Has Already Entered Commercial Service

Tesla recently began offering limited Cybercab rides in Austin, marking an important step in Elon Musk’s plan to build a large driverless transportation network.

The two-seat vehicle is designed specifically for autonomous operation rather than conventional human driving. Tesla’s rollout initially involves a limited number of vehicles and restricted operating areas, with the company planning a broader expansion.

The regulatory investigation therefore arrives at a critical moment for Tesla’s robotaxi strategy.

Why the Vehicle Is Different

Traditional vehicle regulations were largely developed around automobiles controlled by a human driver.

The Cybercab challenges that framework because there is no steering wheel for a passenger to take control of and no conventional pedal system. NHTSA is therefore examining whether Tesla’s determination that certain safety standards were not applicable to the vehicle was justified.

The investigation does not itself establish that Tesla violated federal law.

Instead, regulators are reviewing the basis of the company’s self-certification.

Tesla Used the Industry’s Self-Certification System

U.S. vehicle manufacturers generally certify themselves that their vehicles meet federal safety requirements rather than receiving advance approval for every model from NHTSA.

Regulators can subsequently investigate whether those certifications are supported by the available technical evidence.

Tesla told NHTSA that it had certified the Cybercab as compliant with all applicable standards. The agency is now reviewing how the company reached that conclusion.

Federal Rules Are Already Being Reconsidered

The investigation comes while the U.S. government is separately working on changes to vehicle regulations for autonomous technology.

NHTSA has acknowledged that some existing safety standards were written around vehicles containing conventional human controls. The agency is working on several regulatory changes involving equipment such as brake pedals, mirrors, lighting and windshield systems.

Until those changes are finalized, however, the existing rules remain in effect.

That creates a complicated regulatory environment for companies trying to deploy vehicles designed entirely around autonomous operation.

Tesla Faces a Major Test

The Cybercab is central to Tesla’s ambition to become a major player in the robotaxi industry.

The company hopes autonomous vehicles can eventually operate at large scale, reducing the need for conventional drivers and creating a transportation network based on self-driving technology.

The federal investigation could therefore become an important test of whether Tesla’s approach to vehicle certification can support that expansion.

Other Companies Have Taken a Different Route

Tesla is not the first company to face regulatory questions over autonomous vehicles without traditional driving controls.

Amazon-backed Zoox has also developed a vehicle without a conventional steering wheel and pedals. However, Zoox pursued a regulatory exemption route before receiving approval for limited commercial deployment.

The contrasting approaches could become important as regulators determine how existing vehicle standards should apply to fully autonomous vehicles.

Investigation Covers a Larger Potential Fleet

The NHTSA investigation is not limited simply to the handful of Cybercabs initially operating in Austin.

The agency’s investigation documents identify an estimated population of about 1,000 vehicles, reflecting Tesla’s intended expansion of the technology.

That makes the outcome potentially significant for Tesla’s broader commercial plans.

Tesla’s Autonomous Strategy Under Scrutiny

The Cybercab investigation adds another layer of regulatory attention to Tesla’s autonomous-driving ambitions.

The company has spent years developing its Full Self-Driving technology and has increasingly promoted robotaxis as an important part of its future business.

The Cybercab represents a more radical version of that strategy because the vehicle itself is purpose-built for autonomous operation rather than being a conventional car adapted for driver assistance.

What Happens Next

NHTSA will examine Tesla’s technical data, certification procedures and interpretation of federal safety requirements.

The investigation could ultimately result in no further action, additional regulatory requirements or other measures if officials determine that the certification did not satisfy federal standards.

For now, the agency has not announced a finding that the Cybercab is unsafe or illegal. The investigation is focused on determining whether Tesla’s certification process properly accounted for the vehicle’s unusual design.

A Critical Moment for Driverless Transportation

The Cybercab investigation highlights a larger challenge facing the autonomous-vehicle industry.

Technology is developing faster than some of the regulations originally written for conventional automobiles. Regulators must therefore decide how existing safety rules should apply while creating a framework that allows autonomous transportation to develop without compromising public safety.

For Tesla, the outcome could influence how quickly it can expand its driverless service across the United States.

The Cybercab has already begun its journey onto public roads. Now, federal regulators are taking a close look at whether the legal and technical foundation behind that journey is strong enough for the next stage of Tesla’s robotaxi ambitions.