Waymo has started running fully driverless robotaxis on freeways in San Francisco, Los Angeles, and Phoenix, with no human backup inside, becoming the first company in the U.S. to do so.

Beginning Wednesday, the Alphabet-owned firm said the service is available 24/7, but only to selected riders who’ve opted in to their new features. The move, according to a statement from the company, is part of a gradual rollout that will stretch across its existing urban service areas.

This is the first time any company in the U.S. is offering commercial, highway-level rides with no safety driver in the vehicle. While traditional cabs and rideshare companies like Uber operate freely on freeways, Waymo’s robotaxis had until now stayed off them.

The company confirmed that by removing that restriction, passengers could now take shorter, faster trips, without having to reroute around highways.

Waymo goes driverless on highways as Tesla, others lag behind

Unlike Waymo, rival U.S. firms are still sticking with safety monitors. Tesla, for example, recently launched limited self-driving cab services in Austin that include some freeway routes, but every ride still includes a human in the driver’s seat.

For surface street trips, Tesla keeps a monitor in the front passenger seat. Chief Executive Elon Musk also said the company is testing a custom-built robotaxi called Cybercab, which he claims will enter production by April.

Outside of the United States, WeRide, a China-based robotaxi company, already offers highway rides in Abu Dhabi. But all of their vehicles still include safety drivers.

Waymo, which is based in Mountain View, California, is using the same core sensor system and software for freeway driving that it developed for its urban operations.

The company said it trained its cars for freeway conditions using both closed-course testing and simulations, with a focus on unpredictable events, what it called “rare” and “inevitable” driving conditions.

Waymo claimed its robotaxis are programmed to maintain the flow of highway traffic, keeping up with vehicles around them and staying within legal speed limits. If a vehicle needs to pull off due to an issue, it exits the freeway completely and finds a safe place on nearby roads before stopping.

San Jose and airport zones added to Waymo’s growing map

Beyond the new freeway routes, Waymo is also expanding its service zone in the Bay Area to include San Jose, adding access to San Jose International Airport.

Riders going to or from the airport will be charged the same fee as traditional taxis, the company confirmed.

The firm also said it’s working with San Francisco International Airport, where its vehicles are currently permitted for testing only.

There was no indication of when full-service rides might be available at SFO, but the airport is already being integrated into Waymo’s routing systems.

While expanding into new areas and new roads, Waymo said it does not expect this freeway service to contribute significantly to traffic congestion in any of its cities.

The company’s current fleet numbers 1,000 vehicles in the San Francisco Bay Area, 700 in Los Angeles, 500 in Phoenix, 200 in Austin, and 100 in Atlanta.

The company didn’t give a timeline for when freeway rides might be available in other markets where it operates.

But for now, riders in the three launch cities, who’ve opted in, are already able to experience what Waymo describes as the next step in driverless mobility.

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