MOUNTAIN VIEW, Aug. 16 -- For the past three years, the trucks that moved freight autonomously in the United States have done it in Texas. The state had no ban, and the companies building the technology had the roads. California, where both Aurora Innovation and Kodiak AI are headquartered, told them to go there and do it where the lawyers could not catch them.

On Thursday, that changed. The California Department of Motor Vehicles issued Kodiak the first permit under rules approved in April that lifted the state's ban on autonomous heavy-duty vehicles operating on public roads. Aurora received a parallel permit, allowing both companies to run test trucks with a human safety operator aboard on California asphalt for the first time under a...