Self-driving cars have just turned toward their next frontier: freeways

After expanding on local streets in San Francisco last year, completely driverless rides are coming to US freeways with the safety risks higher.

A Waymo autonomous vehicle on Market Street in San Francisco last November. Picture: Jason Henry/AFP

Last year, self-driving robotaxis took on city streets. Now, they are taking on freeways. Waymo, the self-driving car start-up owned by Google’s parent company, recently started testing driverless rides on freeways in Arizona, using employees as passengers.

It’s a crucial step for the industry. Enabling cars to take freeway routes can cut ride times by as much as half, Waymo has said, and could help the company scale operations. Robotaxi outfits have poured billions into developing this technology and if they can’t offer routes such as airport rides, their path to profitability becomes more uncertain.

Freeway rides would likely be most useful in ferrying passengers to and from airports, as well as driving in cities such as Los Angeles, where freeways are integral to getting across town. Several companies are also moving forward with plans to deliver goods using self-driving trucks on freeways, a market some executives think will produce a quicker return on investment.

The stakes are higher than ever, and patience is running thin for mistakes. It has taken 15 years for Waymo – one of the earliest entrants to the self-driving space – to take this step. Driving on freeways will significantly increase the riskiness of its operations.

Cruise, another self-driving car company, majority-controlled by General Motors, lost its permits to offer driverless rides in San Francisco last year after one of its vehicles dragged a woman – who had been hit by another car – about six metres. The firm paused all operations nationwide shortly thereafter.

Waymo views Los Angeles, a city dense with freeways, as potentially a $3bn market, co-CEO Tekedra Mawakana said at a recent tech conference. This month, the company gained approval from California regulators to start charging for driverless rides on freeways in the Bay Area and parts of the city.

“You’re seeing us make the moves that you have to make to build a profitable business – a long-term, sustainable profitable business,” Mawakana said.

Airport trips might be a rich market for self-driving cars.

For now, Waymo is limiting its driverless rides on the freeway to Waymo employees to work out any kinks ahead of an expansion to the public. The company declined to say when that expansion would be.

Waymo says its rollout on Phoenix, Arizona, freeways has largely been without trouble. Picture: supplied

Aurora, an autonomous technology company focused on trucking, plans to put driverless trucks on freeways across Texas this year.

“That speaks to their confidence,” said Raj Rajkumar, a professor of electrical and computer engineering at Carnegie Mellon University who specialises in self-driving cars. Waymo and other self-driving car companies still have to deal with risks around uncommon freeway driving scenarios, he added.

Waymo has trained its vehicles for different scenarios they might face. But it is difficult to anticipate every obstacle.

On city streets, the cars have faced unexpected hazards, such as people who deliberately run out in front of the self-driving cars to see whether they’ll stop and others who put cones on the cars’ hoods to interfere with their sensors. The passenger has no control over the car if there is an incident.

Public opinion on robotaxis in San Francisco has been mixed, with people quick to criticise the vehicles for mistakes such as stalling and causing traffic jams.

One bad accident could call into question Waymo’s or Aurora’s entire operations, as it did recently with Cruise, and with Uber years before that.

Uber sold off its entire self-driving business after one of its cars travelling at 60km/h struck and killed a woman during testing near Phoenix, Arizona in 2018. Last month, Waymo issued its first-ever recall over a software problem after two of its cars in Phoenix collided with a pick-up truck that was being towed backward.

“Driving on freeways in this country – even for humans – is some of the safest driving there is,” said David Zuby, chief research officer for the US Insurance Institute for Highway Safety.

“But because of the high speeds when crashes occur, the consequences are more severe. You’re more likely to have injuries or fatalities.”

One of the biggest challenges for the vehicles is merging on and off freeway ramps. It requires them to run several calculations at once and make a quick decision while their surroundings are continuously changing – similar to the situation the robotaxis faced making unprotected left-hand turns on city streets. The rollout on Arizona’s freeways has largely been without trouble so far, Waymo says. The cars have been able to successfully navigate on and off ramps and haven’t come to a halt in the middle of the freeway – another issue that occurred on city streets.

When the cars got confused or encountered a problem, they would sometimes stop where they were on the road, backing up traffic and frustrating other drivers who could not communicate with the car.

Sugandha Sangal, a product manager at Waymo, says the vehicles have built-in redundancies to prevent that from happening on fast-moving freeways. If one sensor system fails, there is another in place to help. Over the past year, Waymo vehicles in testing have been involved in a handful of incidents on freeways. Last March, one car in San Francisco hit some tyre scraps while transitioning from one interstate freeway to another, causing damage to the car.

In another incident the same day, a Waymo was driving itself on a boulevard in San Francisco when a safety driver – someone who sits in the driver’s seat of the car and can take over in the case of an emergency – crashed into another car that was stopped in the right-most lane. Both vehicles sustained damage.

Waymo says its rollout on Arizona freeways has largely been without trouble.

Waymo declined to provide more details on the incidents but said building trust with the communities in which they operate is important to them.

Aurora, the driverless technology firm, spent the first few years after its 2017 founding looking for sensor technology that could allow cars to observe activity metres away.

“If we’re driving on the freeway and something breaks at 120km/h, you can’t just stop in the lane,” Aurora CEO Chris Urmson said.

In 2019, Aurora purchased a Montana-based company called Blackmore that was developing a special sensor system. Aurora’s self-driving technology can now detect objects more than 400 metres down the road, Urmson said.

“That was the bet for us that unlocked the possibility to go do trucking,” said Urmson, who previously served as the head of Google’s self-driving car project.

But the company’s path hasn’t been completely without incident. Last year, a truck outfitted with Aurora sensors was sideswiped by a car going more than 100km/h.

Urmson said the truck did all the right things and the incident would have been very difficult to avoid. He aims to have his trucks on freeways without safety drivers by year’s end.

Other competitors in the space say they are still years out.

Amazon-owned Zoox plans to launch public rides in Las Vegas this year, with freeway driving in the very distant future. But even now, company executives recognise its potential.

“Once we can unlock driving on (the busy 101 freeway that passes through California) then that’s a whole different ballgame,” said Bryan O’Sullivan, a senior vice-president at Zoox.

Cruise, before it lost its permits, wasn’t planning to get on the freeway soon, according to people familiar with the matter. The company’s immediate road map was focused on expanding to more cities, only on local streets.

A local 23-year-old college student named Joel Johnson was one of the first members of the public to ride in a Waymo in downtown Phoenix when the company started rolling out passenger rides in 2022.

Johnson has been following Waymo for years and has taken dozens of rides, which he documents via his YouTube channel – JJRicks – with 10,000 subscribers.

“We’ve gone from good but jerky cars with safety drivers to extremely smooth and empty cars,” Johnson said. “If they say, ‘We’re ready for freeway’, then I say, ‘bring it on’.”

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