Waymo, the self-driving unit of Alphabet Inc, said its vehicles had covered more than 20 million miles (32.2 million km) on public roads since its creation in 2009.
“It took us a decade to drive the first 10 million miles but just over one year to complete these last 10 million,” the company said in a statement late on Monday.
Large tech companies, big automakers and well-funded startups have been testing self-driving vehicles, but for the most part real passengers have not been included in the plan.
Waymo, considered a leader in the global race to deploy autonomous vehicles, has begun offering a limited number of fully automated rides for the public without backup drivers in its cars.
