Federal security investigators have sent Tesla a detailed list of questions about its upcoming Robotaxi service, part of an investigation into how the company's "full autonomous driving (supervised) software runs under low visibility conditions.

The National Highway Traffic Safety Administration’s Office of Defect Investigation hopes to provide additional information about fully autonomous driving (supervised) or “FSD” to “understand how Tesla plans to evaluate its vehicles and drive automation technology to use on public roads,” according to Reuters. ”

Tesla is not quiet about plans to launch robotics services for paid vehicles in Austin, Texas, and used its own fleet vehicles in June. But it seems Tesla's April 23 article about X attracted the attention of federal regulators.

The article quoted in the letter reads: "The FSD Supervised Ride Service has been conducted among early employees in Austin and the San Francisco Bay Area, and we have completed 1.5k travel and 15,000 miles of driving. This service can help us develop and validate FSD networks, mobile applications, vehicle allocation, mission control and remote assistance operations."

NHTSA conducted an investigation into Tesla's "full autonomous driving (supervisory)" software in October, after four crashes in low visibility. Tesla's FSD software is an advanced driver-assistance system that requires the driver to put his hands on the steering wheel even when dealing with certain driving operations such as braking and steering under certain environments and conditions.

Tesla CEO Elon Musk said the robot will use an unreleased "unsupervised" version of its complete autonomous driving software.

The agency sent Tesla a series of questions in a May letter to determine whether the autonomous driving system in its planned robot is the same or similar to the supervised FSD. The agency requested detailed information on fleet sizes, as well as what vehicle models will be used in the Robotaxi service, how Tesla plans to determine whether its robotic system is safe, and whether the autonomous driving system has anything to do with the FSD-supervised product.

Investigators also asked Tesla to describe it "intention to ensure the security of its robotic operations in reduced road visibility conditions such as Sun Glare, Fog, Fog, Airlande Dust, Lain or Snow."