The National Highway Traffic Safety Administration announced on September 21 that it is launching a preliminary evaluation of the aftermarket driver-assist system produced by San Diego-based Comma.AI. The investigation follows five reported crashes in which the device was active, two of them resulting in three fatalities and a total of fourteen injuries, including eleven classified as serious.
Comma.AI, founded in 2015 by the famed hacker George Holz, markets a plug-in unit that connects to a vehicle’s OBD-II port and runs the open-source openpilot software. The company claims the hardware, known as the Comma Four, supports more than 325 models from twenty-seven automakers and is currently used by over thirty thousand drivers across the United States.
How the Comma Four system is intended to work
The device combines a forward-facing camera supplied by Comma.AI with the car’s native sensors. According to the maker, the suite delivers adaptive cruise control and automated lane centering allowing the vehicle to accelerate, brake and steer with minimal driver input. The software relies on a neural network that has been trained on millions of miles of driving data, enabling it to predict road geometry and the behavior of surrounding traffic. Nevertheless, the company stresses that drivers must remain alert keep their hands near the wheel and be ready to intervene at any moment.
Crash details that triggered the federal review
Within a short span, five incidents were reported to NHTSA’s Office of Defects Investigation (ODI). In each case, the Comma Four was either powered on or engaged when the vehicle collided with a stopped or slowly moving car occupying the same lane. Preliminary data suggests the system may have failed to correctly detect those obstacles, leading to rear-end impacts. Two of the crashes produced three deaths, while the remaining three resulted in eleven serious injuries and three additional minor injuries, bringing the total injury count to fourteen.
ODI’s announcement emphasized that the evaluation will scrutinize the system’s status at the moment of each crash and assess whether any modified version of the openpilot code—often referred to as a “fork”—was in use. The agency also plans to review the safeguards that are supposed to prevent operation under unsafe conditions.
Industry context and reactions
Comma.AI’s approach differs from the fully integrated autonomous platforms of larger players such as Tesla or Waymo, because it is sold directly to consumers and installed in roughly fifteen minutes. The promise of a “hands-free” experience for cars already on the road has attracted a niche community of enthusiasts, including journalists like Emmet White, who have tested the product on their personal vehicles.
The NHTSA probe underscores the challenges of aftermarket automation, where hardware and software upgrades are applied to vehicles that were not originally designed for full autonomy. As regulators gather data, the outcome could shape future guidance on how third-party autopilot systems must demonstrate reliable detection of stationary hazards and enforce driver attentiveness.
While Comma.AI has not yet issued a public response, the company’s founder George Holz remains a vocal advocate for open-source vehicle technology. The pending investigation will likely determine whether the current safety claims hold up under scrutiny and could influence the broader trajectory of plug-in driver assistance solutions.
