There are many companies testing self-driving cars in the United States and elsewhere.
Waymo did not specify how many cars will be on the roads for the beta program, but described it as a "fleet".
Waymo, the driverless auto arm of parent company Alphabet, revealed the "next phase" of the project, which is one of the most developed in autonomous vehicle in the world.
Iconic Marvel writer Brian Michael Bendis moves to DC
Will Marvel take this opportunity to refresh its pool of talent, or will we just see a reshuffle of established writers? Marvel has since released a statement on the long-time writer's departure. "Change is good", he wrote on Twitter .
Italian legend Andrea Pirlo thanks NYCFC, retires from soccer
Every day you have physical problems, you can not train as you want because you always have some problem, ' he told La Gazzetta dello Sport .
Sleep-deprivation similar to being drunk, leads to memory lapses
The scientists say the brain is performing in a sleep-like state while awake which could lead to accidents and low productivity. Previous studies have linked sleep deprivation to a heightened risk of depression, obesity, diabetes, heart attacks and stroke.
Previously, Waymo's self-driving cars had been operating with a human sitting in the driver's seat.
Despite there being no driver behind the wheel, a Waymo employee will remain in the vehicle at all times. With Waymo officially pulling safety driver's from the front seat, the West Coast company is pulling ahead and again threatening to beat Detroit at its own game.
Residents participating in the trial will also be able to use them exactly as they use the test vehicles with safety chauffeurs today - for any trips within the designated area, whether for commutes, trips to go shopping, heading to school or whatever their transportation needs.
Waymo's vehicles will now be able to take people who signed up to be early testers of the service anywhere in the greater Phoenix area, which the company says will soon comprise an area larger than that of Greater London. During this next phase, Waymo will slowly expand the area it operates in to cover 600 square miles.