In a bid to promote the autonomous technology, the self-driving unit of Alphabet, Waymo is offering free rides to the Arizona residents in its self-driving cars.

Waymo chief executive John Krafcik said: "We'll be accepting hundreds of people with diverse backgrounds and transportation needs who want to ride in and give feedback about Waymo's self-driving cars."

He further added: "The goal of this program, is to give participants access to our fleet every day, at any time, to go anywhere within an area that's about twice the size of San Francisco."

Krafcik also said that the company wants "as many people as possible to experience" the technology and it will be brought to more communities soon.

"Our early riders will play an important role in shaping the way we bring self-driving technology into the world - through personal cars, public transportation, ride-hailing, logistics and more," he said.

Waymo also revealed that they were already doing a trail in Phoenix area over the last month, where they were taking participants to schools, offices, game practices and so on in self-driving cars - using Chrysler Pacifica cars in Arizona.

According to the CEO of Chrysler's parent company FCA, Sergio Marchionne the collaboration with Waymo "has been advantageous for both companies as we continue to work together to fully understand the steps needed to bring self-driving vehicles to market."

Recently Apple has also obtained a permit to test their self-driving cars in California.

Among other companies, German luxury carmaker Daimler and auto parts supplier Bosch have announced plans this month only, to work together on developing completely driverless cars within next few years. Tesla is also stepping up efforts in the field.

Google and Uber are presently embroiling in a legal battle, as Alphabet filed a lawsuit earlier this year accusing Uber of stealing its autonomous-car's technology. And this latest effort by Google of offering free rides to public seems to appear as a challenge to Uber, as the Waymo has already undergone millions of miles of testing.