US Regulators Investigate Comma.ai Driver-Assist System After Two Fatal Crashes

US auto safety regulators have opened an investigation into Comma.ai, the maker of a popular open-source driver-assistance system, following at least two fatal crashes linked to vehicles using the technology.

The National Highway Traffic Safety Administration is examining incidents in which drivers were reportedly using "forked" versions of Comma's software — modified copies of the company's open-source code that are not officially maintained or certified by Comma itself. The distinction is significant because it raises questions about how regulators should treat driver-assistance systems built on open-source foundations but altered by third parties or individual users.

Comma's flagship product, known as openpilot, is designed to add adaptive cruise control and lane-keeping features to compatible vehicles, positioning itself as a lower-cost alternative to automakers' built-in driver-assistance suites such as Tesla's Autopilot or GM's Super Cruise. Because the software is open-source, technically skilled users can modify it, which has made it popular among hobbyists but also complicates oversight.

Details of the two fatal crashes under review have not been fully disclosed, and it remains unclear whether the forked software variants played a direct role in the collisions or whether other factors were involved. NHTSA investigations into driver-assistance systems typically examine vehicle data, crash reports and any known defects before determining whether further regulatory action, such as a recall or safety directive, is warranted.

The probe adds Comma to a growing list of driver-assistance and partial-automation providers facing regulatory scrutiny in the US, as adoption of such systems expands faster than the rules governing their use and modification. Comma has not yet issued a detailed public response to the investigation.