Waymo robotaxis are now making freeway trips in Los Angeles, San Francisco and Phoenix

Sixteen years ago, engineers working on Google’s self-driving project conducted their first tests of self-driving vehicles on the highway connecting Silicon Valley to San Francisco.

The company will eventually become Waymo, and self-driving vehicle testing will expand — and spread to other cities. Eventually, the company launched commercial robotaxi services in Phoenix, San Francisco, and Los Angeles. Other cities soon followed.

But highways, despite some of those early tests, will remain elusive. Until today.

Waymo said Wednesday it will begin offering robo-taxi rides using freeways across San Francisco, Phoenix and Los Angeles, a significant expansion for the company that it says will reduce ride times by up to 50%. This statistic could help attract a whole new group of users who need to travel between multiple towns and suburbs within the greater San Francisco Bay Area or speed up commutes across the sprawling Los Angeles and Phoenix metro areas.

Using highways is also essential for Waymo to offer trips to and from San Francisco Airport, a location the company is currently testing.

The service will not be offered to all Waymo riders initially, the company said. Waymo riders who want to try freeway rides can note their preferences in the Waymo app. Once a passenger praises a ride, it may be matched with a freeway ride, according to the company.

The company’s robo-taxi routes will now extend to San Jose, an expansion that will create a 260-mile unified service area across the peninsula, according to Waymo. The company said it will also begin pickup and drop-off service at San Jose Mineta International Airport. It already offers curbside service to Sky Harbor Phoenix International Airport.

“Highway driving is one of those things that is very easy to learn, but very difficult to master when we’re talking about full self-driving without a human driver as a backup, at scale,” Waymo co-CEO Dmitry Dolgov said in a briefing with reporters. “It took some time to do it right, with a strong focus on system safety and reliability.”

Waymo’s robotic car has been spotted on highways for months. TechCrunch did a test flight last year in the Phoenix area that included freeways. The company has been offering trips to employees for more than a year. It has also expanded the scope of testing to include closed-course and simulation

While many assume highway driving is easier, it comes with its own set of challenges, lead software engineer Pierre Kreitmann said at a recent press conference. He noted that critical events occur less often on highways, which means there are fewer opportunities to expose Waymo’s self-driving system to rare scenarios and demonstrate how the system performs when it really matters. The company chose to enhance its driving on public roads through a combination of closed track and simulator testing.

This extensive testing and validation of the software was done to ensure vehicles move smoothly and safely between highways and surface streets, recognizing and adapting to the unique context of the road around them, Kreitman said.

Waymo has also expanded its operational protocols, including how it coordinates with safety officials like the California Highway Patrol, now that its robotaxis are on highways.