Two key players in Silicon Valley's battle to define the future of transportation are teaming up, taking aim at a common enemy.

Waymo, the self-driving division of Google's parent Alphabet, and ride-hailing company Lyft are partnering to test driverless car technology, the companies have confirmed.

Both companies face a bitter foe in Uber, and are seizing the moment as their rival stumbles. Uber, which is valued privately by investors at close to $US70 billion ($94 billion), dwarfs Lyft (which is currently only available in the US) in the ride-sharing arena, while Google is neck-and-neck with Uber in a race to develop autonomous vehicles.

"We can confirm that we are partnering with Waymo to safely and responsibly launch self-driving vehicle pilots," a Lyft spokeswoman said in an email. "Waymo holds today's best self-driving technology, and collaborating with them will accelerate our shared vision of improving lives with the world's best transportation."

Waymo also confirmed the partnership, which was first reported by the New York Times. "We're looking forward to working with Lyft to explore new self-driving products that will make our roads safer and transportation more accessible," a spokesman said in an emailed statement. "Lyft's vision and commitment to improving the way cities move will help Waymo's self-driving technology reach more people, in more places."

Uber has faced a series of ever-worsening setbacks that have made the seemingly unstoppable juggernaut very vulnerable. The company is in a legal battle with Waymo over the potential theft of trade secrets from Waymo's self-driving car program. This week a district judge referred the case to federal criminal prosecutors for investigation. Meanwhile, Lyft has been benefiting from a wave of consumers that have quit Uber in disgust following missteps during the Trump administration's immigration ban, a sexual harassment scandal, and a leaked video of Uber's chief executive cursing at a driver.

The deal appears to play off the assets each company brings to the table. Lyft, which is privately valued at $US7.5 billion, doesn't have the resources to invest in self-driving car technology. The company has said it is not going to attempt to do so. But Lyft has a network of consumers that use the company's app. Waymo, which is not consumer-facing, could benefit from that network as it races to bring the technology to the public.

The Washington Post