Waymo LLC will start testing its autonomous vehicles on San Francisco freeways later this week without a human driver aboard.

The move, which TechCrunch reported today, marks the latest milestone in the Alphabet Inc. unit’s efforts to build a large-scale autonomous ride-hailing service. Waymo started carrying out similar freeway tests in Phoenix earlier this year. According to Gizmodo, Waymo hopes that using freeways will enable its vehicles to reach their destinations faster and thereby provide a better user experience.

Parent company Alphabet last month announced plans to invest $5 billion in Waymo to support its commercialization efforts. The autonomous vehicle developer previously raised more than $4.5 billion over two funding rounds that included the participation of AutoNation Inc., Fidelity Management and other third-party investors. Waymo faces competition from several companies including General Motors Co.’s Cruise unit, which has likewise raised billions of dollars in funding.

Waymo’s vehicles are powered by an autonomous driving system called Driver. It uses an array of cameras, lidar sensors and radar units to map out the environment of the vehicle in which it’s installed. Onboard artificial intelligence models turn the data collected by those sensors into driving decisions. 

Waymo’s vehicles don’t rely on their sensors alone to navigate public roads. Before the Alphabet unit brings its ride-hailing service to a new city, its engineers create a detailed map of the local roads and curbs. Those maps, which also contain more granular details such as stop signs, are used by Waymo’s autonomous driving system to plan travel routes.

In cases when a vehicle is unsure which route to take, it can request help from a team of human agents. The agent who fields the request can access data from the vehicle’s sensors to understand the situation at hand and provide pointers. To further reduce the risk of errors, Waymo’s Driver system includes several backup components designed to activate in the event of a malfunction. 

In San Francisco, Waymo vehicles’ newly enabled ability to operate on freeways autonomously will be rolled out gradually. At first, the feature will be available only to the Alphabet unit’s employees. The initial test is set to see Waymo pilot the capability outside rush hours with “less than a handful” of vehicles.

The development comes about five months after Waymo received the regulatory approvals necessary to operate its vehicles on San Francisco freeways without a safety driver aboard. It launched fully autonomous freeway tests in Phoenix at the start of the year. Los Angeles and Austin, where the feature is not yet enabled, round out the list of cities where Waymo operates its ride-hailing service.

Waymo recently expanded its service areas in Los Angeles and San Francisco to additional suburbs. The $5 billion in new funding that the autonomous vehicle maker has secured from Alphabet last month may help accelerate the pace at which it adds new locations. In June, rival Cruise likewise raised capital from its parent company to support commercialization initiatives.

Photo: Waymo