MOUNTAIN VIEW, Calif. -- Google's self-driving cars aren't yet ready to hit the road as robotic taxis. But the rapid rollout of prototypes this summer for testing in Austin, Texas, suggests that the company may be zeroing in on a city for when that day arrives.

Google, which now operates under a holding company called Alphabet Inc., sent an experimental self-driving car to Austin in early July. It was the first extended trip outside California for one of Google's cars, which have now logged 1.2 million miles in autonomous mode since the project began in 2009.

Three months later, Google has brought 14 self-driving vehicles to Austin -- nearly one-third of its current testing fleet, according to the project's monthly report.

That suggests Google may be thinking of choosing Austin for a pilot project that puts its cars in public hands. Residents of the trend-setting state capital and college town have been quick to embrace services such as Uber and Car2Go that Google may emulate with its podlike cars.

Texas has been hesitant to regulate self-driving cars. Google employs hundreds of people in Austin and has used the city as a proving ground. Blizzards, a daunting challenge for self-driving cars, are rare.

And the self-contained nature of Austin may better lend itself to on-demand robocars than a sprawling metropolitan area such as San Francisco, says Thomas Gage, an autonomous-driving expert who is CEO of Marconi Pacific, a technology consultancy in suburban Washington.

"If the goal is to offer mobility as a service," Gage said, "it seems logical that Google would do it the same way Uber has rolled out mobility as a service: market by market."

There are signs of a growing maturity; last month, Google hired John Krafcik, a former president of TrueCar Inc. and CEO of Hyundai Motor America, to manage the project. Still, Google says it hasn't yet decided how to commercialize the technology.

"It remains open exactly how we're going to roll it out," Google co-founder Sergey Brin said at a late September press event. "In the near term, there's a real upshot of making it a service, which enables a lot of people to try it out."