Cruise robotaxis are back on the road… well, kind of. Though General Motors pulled the plug on its self-driving taxi business last year, the automaker has been quietly repurposing a few of the vehicles as it seeks to develop new driver-assistance technologies.

This week, WIRED spotted a GM Bolt electric hatchback on the San Francisco-Oakland Bay Bridge, and later saw a similar vehicle on Interstate 880 near Oakland. In each instance, the car was being driven by a human. But it held equipment on the roof such as lidar sensors that resembled the setup from the Cruise ride-hailing system. The vehicle had “Mint” written on the hood, but didn’t include any visually apparent Cruise branding.

GM spokesperson Chaiti Sen confirms to WIRED that the company is indeed “using a limited number of Cruise Bolt vehicles on select highways in Michigan, Texas and Bay Area for testing with trained drivers to further develop simulation models and advanced driver assistance systems.” She adds, “This is internal testing and does not involve public passengers.”

GM removed the orange-and-white Cruise logo from the cars’ sides after it took full ownership of the unit in February, she says. The recent activity began in Michigan and Texas in February and the San Francisco Bay Area-region in mid-April, Sen says. Cruise had named each vehicle in its fleet, and Sen confirmed that “Mint” has been among the vehicles newly active in the Bay Area.

The testing shows for the first time how GM is beginning to give a second life to a fleet of no less than hundreds of vehicles left over from a costly project that ran aground.

GM initially acquired a majority stake in San Francisco-based Cruise in 2016, and invested more than $8 billion into developing a robotaxi service. The operation was off to a fast start and eyeing a rapid expansion until October 2023, when a Cruis...