No federal safety standards govern aftermarket driving-aid devices, experts say
With the press of a button, Matt Peak, a retired aircraft mechanic in Brighton, Mich., takes his hands off the steering wheel of his Chrysler Pacifica minivan — something the vehicle’s maker never intended — and lets the car cruise at 55 miles an hour past subdivisions and a golf course near his home. The setup is an aftermarket device from Comma.ai that cost him $1,000 and required about an hour to install. “Scary as heck, the first time you do it,” Peak said, resting his hands on his knees during a drive with a Wall Street Journal reporter. Now, he said, it is part of his everyday routine.
The device sits at the center of a federal safety investigation. At least five crashes, including three deaths and 14 injuries, have been linked to Comma.ai, according to the National Highway Traffic Safety Administration, which opened an investigation into the device in September. Police and incident reports viewed by The Wall Street Journal describe drivers who fell asleep or slammed into stopped vehicles while using it.
Comma.ai says its kit works on more than 350 vehicle models dating back to 2014, enabling hands-free driving that most automakers don’t — or can’t — offer themselves. The aftermarket approach is testing the frontiers of a technology that automakers increasingly see as a lucrative subscription business. Driving-assistance systems span a range of capabilities, from lane-assist to adaptive cruise control to supervised hands-free driving; no car company offers fully autonomous technology, and even Tesla’s Full Self-Driving is described as requiring human supervision. Tesla sells FSD as a $99 monthly feature that allows hands-free driving and point-to-point navigation, while General Motors’ Super Cruise and Ford’s BlueCruise permit hands-off driving on certain highways.
The device is legal, highlighting what experts describe as gray areas around automated driving-assistance technologies. There are no federal safety standards for this technology, and NHTSA has had its hands full investigating the safety of automaker-designed systems, said Michael Brooks, executive director of the Center for Auto Safety, a Washington, D.C., nonprofit. “The agency is struggling to keep up with advanced driver tech, and this is another area that deserves more scrutiny,” he said.
Comma.ai said it offers “one of the most mature driver-assistance systems available,” that its users have logged more than 400 million miles collectively, and that its system adds driver-monitoring features most cars lack. The company noted that its software is free, so drivers pay only for the hardware kit for their vehicle. “We don’t believe in hiding features, especially safety features, behind subscriptions or as an upsell,” Chief Product Officer Adeeb Shihadeh said.
NHTSA said it does not comment on open investigations and that drivers are fully responsible for operating a vehicle and must remain attentive when using a partially automated system. About 30,000 cars have Comma.ai equipment installed. The company is by far the leading player in do-it-yourself self-driving kits; Epilog, a San Francisco artificial-intelligence company, makes a similar device called SideCar that it said works on more than 300 vehicles. Epilog did not respond to a request for comment.
In vehicles equipped with adaptive cruise control and lane-keeping capabilities, third-party devices like Comma.ai’s work by taking control of the steering, braking and powertrain functions. They essentially mimic the language in which the car’s hardware communicates, said Florian Frischmuth, vice president of digital engineering at software consulting firm Envorso. Comma.ai released its latest kit, Comma Four, last November; the device includes an inward-facing camera that tracks the driver’s eyes and head position and issues alerts if it detects inattention.
Comma.ai, founded by coder George Hotz, has sold the kits since 2020, though regulators scrutinized the company’s plans even earlier. Hotz planned a decade ago to sell hardware and software that would let car owners install semiautonomous driving aids on some vehicles. He abandoned the effort after regulators began asking questions about the product’s safety and opted to release the software behind it for free.
Automakers say consumers are free to modify cars at their own risk, and Comma.ai’s device might void a warranty. Comma.ai said federal law requires automakers to honor warranties unless they can show that a particular fault was caused by the aftermarket device. Some experts expect car companies to block aftermarket systems in future vehicles, but blocking a device like Comma.ai’s is not possible for most cars on the road today, Frischmuth said, because those vehicles cannot detect when a third-party system has taken control. “It was basically a door with no lock,” he said. “Anybody could walk right through.”
NHTSA started receiving reports last fall of crashes involving vehicles equipped with Comma.ai’s device, records show. The agency said preliminary data it reviewed “suggests that the Comma system may not have adequately detected or responded to the in-lane vehicles.” In one 2025 case, Allen Robberson slammed a used Honda Accord into the back of another car at a red light in Missouri. Robberson’s car was going 80 mph with a Comma.ai device enabled, and the crash left one occupant of the stopped vehicle with severe injuries, according to a lawsuit. Robberson, who was later charged with a misdemeanor, referred a request for comment to an attorney who declined to comment. After the crash, according to a police report viewed by The Wall Street Journal, he told first responders that “he had set the vehicle’s automation to allow him to sleep.”
Comma.ai declined to comment on the accident or the government probe but stressed that its system never obviates the driver’s role. “Nothing for sale today is a self-driving car (despite any names to the contrary), and no driver should treat one like it is,” a spokesperson said.