Waymo will begin rolling out its driverless vehicles in four new cities in the coming weeks, furthering its U.S. expansion and building on its lead over domestic rivals Tesla and Zoox, which is owned by Amazon .
Alphabet 's robotaxi division will soon start offering fully autonomous rides in San Diego, Las Vegas, Tampa, Florida, and Denver, the company said Wednesday. While the launch will initially be for Alphabet employees, the rollout will then extend to the public.
Waymo, which first announced the expansion plans last year, currently operates driverless cars in more than 10 cities. While Waymo has a big head start in the market, Tesla and Zoox are both slowly pushing into new cities. Zoox is preparing to launch its robotaxi service to some members of the public in Austin, Texas, and Miami later this year, and Tesla is going beyond Austin into other parts of Texas as well as to Miami.
As of May, Waymo's domestic fleet included about 4,000 robotaxis equipped with the company's fifth- and sixth-generation automated driving systems, according to filings with U.S. auto safety regulators.
Waymo's latest announcement comes as the company confronts challenges that are arising as more of its cars hit the road. Some of its vehicles have driven into flooded roadways following extreme weather events, and during the Fourth of July celebrations, a number of vehicles in San Francisco were stuck in traffic for so long that their batteries died, while another was seen driving into fireworks.
In February, Waymo raised $16 billion from Alphabet and other backers. The company plans to begin service in London, its first international market, later this year, having driven more than 20 million overall autonomous rides, with its sights set on hitting 1 million weekly trips by the end of the year.
β CNBC's Lora Kolodny contributed to this report.
WATCH: Waymo and Uber end pilot partnership in Phoenix