Google's launch of a carpooling service Monday marks the beginning of its seemingly inevitable entry into the ridesharing wars.

The pilot program, which is being offered via Google's Waze navigation app, aims to connect commuters who need a ride with drivers who can supply one. In exchange, riders will help cover the drivers' fuel costs. Consolidating rides means fewer cars on the road — which is better for traffic congestion and the environment, according to Waze.

"Waze Carpool connects riders and drivers with nearly identical commutes based on their home and work addresses," the company says in a section of its website. "Thanks to Waze advanced mapping capabilities, the platform connects carpool partners from the same local community."

The invite-only service is being introduced at first to 25,000 people who work for Adobe and Wal-Mart in the San Francisco area, according to the Wall Street Journal. Carpool riders will need to download a separate app, called Waze Rider, which is designed to interact with Waze's primary app for drivers. As the Journal notes, Uber and Google have had a complicated relationship; in 2013, Google Ventures invested hundreds of millions of dollars into Uber, but the two companies have since grown apart as Uber has matured.

The Google-backed carpool experiment differs significantly from some of the biggest companies in the ride-hailing industry, such as Uber and Lyft, which are explicitly designed to provide drivers with a supplementary source of income. These mainstream companies also tout the work flexibility that their drivers enjoy; whether it's serving weekday commuters or late-night partiers, the contractors can choose to drive during the times that suit them best.

By contrast, Waze Carpool drivers won't be paid — at least for now — beyond the 54 cents per mile that riders will be charged for gas and other routine expenses. And Waze Carpool will only be available to users twice a day, during the morning and evening rush hours.

Still, the offering represents an important first step by Google into ridesharing, one that sets the stage for a future service that could potentially involve not just human drivers, but self-driving cars.

"Google is laying the groundwork for an autonomous vehicle economy," said Karl Brauer, an analyst at Kelley Blue Book.

Google declined to comment, referring me instead to Waze, which also declined to comment beyond simply confirming the pilot test.

Uber has publicly flirted with autonomous ride-hailing in the past, and it's one that Google would be well-positioned to take on as well. The two companies could someday find themselves going head-to-head over what many analysts predict to be the future of transportation, particularly in urban areas. In places such as New York or San Francisco, costly car ownership may be replaced by on-demand car services that are operated almost entirely by machine.

To some analysts, the transition has already begun.

"They're an autonomous vehicle with a meat-based algorithm behind the wheel," said Reilly Brennan, who directs Stanford University's Revs mobility research program, of the current incarnation of Uber, at a panel on automotive technology at South by Southwest earlier this year.

Last month, Uber, Google and Ford launched a coalition aimed at pushing driverless vehicles to market. And combined with the driver data being gathered from the thousands of trips Waze Carpool may make over the coming months, Google's own research into vehicle automation and artificial intelligence will likely create the right conditions for an expansion into driverless ridesharing.

Waze Carpool is already a relative latecomer to the ridesharing scene, which proves to be a disadvantage. The app economy has become tremendously saturated, according to Julie Ask, an analyst at Forrester Research, making it difficult for any single new app to break through.

"Few brands are so indispensable to consumers that they convert into an icon on the smartphone," Ask wrote in a 2015 report.

For many drivers, Waze's popular main app already enjoys that status. The newer Waze Rider app may be a different story, particularly if it's more limited in functionality compared to other, competing ride-hailing mainstays like Uber.

But that shouldn't matter too much if Google indeed views Waze Carpool as merely a stepping stone to something else.