NHTSA is examining three deaths, 11 injuries and whether Comma devices detected stopped vehicles, including when modified versions of its open-source software were running.
By [RuntimeWire Staff](https://runtimewire.com/author/runtimewire-staff)
· Published
Primary source: [Business Insider](https://www.businessinsider.com/comma-ai-driving-tech-faces-federal-probe-after-fatal-crashes-2026-9)
Why it matters #
NHTSA's investigation puts Comma AI's open-source, aftermarket model under scrutiny: investigators will examine both company devices and modified OpenPilot forks, while the five crash reports include three deaths and 11 injuries.
The National Highway Traffic Safety Administration opened a preliminary investigation on September 21st into Comma AI's driver-assistance devices, after five reported crashes in which equipped vehicles struck slow-moving or stopped vehicles in their lanes. The crashes left three people dead and 11 injured, according to the agency's investigation materials reported by Business Insider.
The inquiry reaches into the model George Hotz has pursued since founding Comma AI in 2015: add driver assistance to cars already on the road, rather than wait for automakers to build it in. NHTSA's questions now focus on a central safety test for that idea: whether the system can respond when a vehicle ahead is stopped or moving slowly.
NHTSA says it confirmed that Comma systems were powered on or engaged in multiple crashes. The agency's preliminary data suggests the system "may not have adequately detected or responded to the in-lane vehicles." That is an investigative assessment, not a finding that a defect exists. The probe will examine the devices, how they performed, and what software was active in each incident.
The open-source question
Comma AI sells hardware that runs OpenPilot, its open-source driving software. The investigation covers comma three, comma 3X and comma four devices, as well as OpenPilot and modified versions, or forks, built from it. NHTSA says it will consider shared components if a fork was involved in a crash. Ars Technica reported that at least two of the five crashes involved forks, including a fatal crash involving software called FrogPilot.
That detail puts the focus on a difficult boundary for Comma AI: the product is a company-sold device, while the software ecosystem includes code changed and distributed by outside developers. NHTSA is looking into which versions were running, so the reports do not establish that the same software was involved in all five incidents or that Comma AI's official build caused each crash.
Hotz's history with regulators began early in Comma AI's life. In 2016, after NHTSA sought information about the planned comma one device, Hotz canceled the product and Comma AI released its driving software as open source. TechCrunch's account of the cancellation captured a founder willing to change course rather than launch a product under unresolved regulatory pressure. A decade later, that open approach has widened participation in the software while giving investigators a more complicated set of versions to examine.
Hotz no longer manages Comma AI's day-to-day operations, Business Insider reported, but remains a major owner. He built the company around an aftermarket alternative to factory driver-assistance packages, and the current Comma Four continues that pitch: Comma says it adds steering, acceleration and braking assistance to compatible cars. The product listing puts it at $999. Comma also tells drivers to stay alert and ready to take control at all times.
RuntimeWire recently reported that Comma Four supports more than 325 car models while still requiring an attentive driver in our September coverage. That distinction is crucial here. Comma markets a hands-free experience, but describes the system as driver assistance, not a replacement for the person behind the wheel. NHTSA's investigation is testing how that promise and responsibility hold up in the incidents under review.
One crash in the agency's reporting appears to match a February 2026 incident in Louisiana, in which a Toyota RAV4 struck an unoccupied police vehicle stopped in a highway lane with emergency lights on. Two passengers in the Toyota died. The police account did not identify Comma hardware or software, so the connection remains an apparent match, not a confirmed identification.
Comma's support material also lists stationary vehicles in the same lane among conditions that can affect OpenPilot's adaptive cruise control. That warning does not establish what happened in any specific crash. It does show why investigators are focusing on stopped vehicles and on whether safeguards, software versions and driver monitoring worked as intended.
The preliminary evaluation is an early stage of a federal inquiry, not a recall or a final safety determination. For Comma AI, the immediate question is which hardware and software combinations were involved in each crash. For Hotz's founding bet, the larger test is whether a retrofit system with an open software base can extend assistance to more drivers while maintaining clear, verifiable safety boundaries across versions and vehicles.