The Report

Could driverless cars render public transit obsolete?

Could driverless cars render public transit obsolete?

Posting in Transportation | From Issue 17 May 5 & 12, 2014

Autonomous, self-driving vehicles promise to revolutionize commuting and travel. They will also disrupt city life and urban transportation systems.

Driverless car advocates love talking up the potential safety benefits promised by the hundreds of sensors and transponders that maintain safe distances between vehicles, counteracting the sometimes-fatal mistakes humans make behind the wheel. Or they gush about the conveniences they might bring, by freeing vehicle operators to take care of other tasks in transit, like they might be able to do on a bus, train or subway.

Far less, however, has been said about the potential of self-driving vehicles (SDVs) to significantly disrupt public transit systems — both in positive and negative ways. 

"There has been a lot of buzz in autonomous vehicles, but much of that work has focused on technology," says Chandra Bhat, who directs the Center for Transportation Research
 at the University of Texas at Austin. "There has been relatively little in the area of 'how do we make our transportation infrastructure handle this?'"

That's a question more planners and transportation industry people are beginning to ponder, especially because Google is equipping its autonomous cars to safely navigate city streets. Based on automaker predictions and technology advances, SDVs could be ready for mass deployment as soon as 2020. Yet, that's just one piece of the puzzle. "The automotive and technology track is evolving very quickly, whereas the policy and institutional part is moving at a glacial pace," says Ananda Rama K. K. Palanisamy, senior transportation management specialist with Citizant

Still, Palanisamy thinks SDVs won't hit roadways in anything approaching critical mass until — at the earliest —the mid-2030s, by which time regulators may have fleshed out how to deal with the myriad liability and infrastructure conundrums driverless cars will doubtlessly create.

In some visions of the future, SDVs usurp today's commuter car altogether. Why would you drive to the nearest rapid transit rail line and pay for parking when an SDV could whisk you to the station in the morning and then return to your own driveway for the day? Dial it up on your way home, and your autonomous ride could be waiting when you arrive back in the evening, like a suburban soccer mom waiting for her children to be released from school.

Remove commuters' demands for street and lot parking, and SDVs could completely change a city's landscape. Some cities devote a third of their land to parking, so SDVs could free up significant real estate for other uses, from parks to residences to office space. Cutting back on the land used for parking might even reduce real estate costs.

What's more, some people who own a car (or a second family car) only for commuting could ditch the rig altogether and instead rely on driverless jitneys. That's one vision that Robin Chase, who founded car-sharing service Zipcar, laid out recently in The Atlantic. If you take this argument to its extreme, cars would become a municipal service, not an asset.

"This is where it gets interesting for planners," says Steve Boland, transportation planner at consulting company Nelson\Nygaard. "There is a lot of talk about how [SDVs] could increase capacity for infrastructure. Sure, you can squeeze more cars on freeways, but the constraints on city streets are different. If all the vehicles on the road were driverless taxis, there would not be parking problems."

But in a mixed population of driverless and non-autonomous cars — which certainly would be the case for most cities during any transition — the potential benefits of automation are less clear. For one thing, they won't necessarily cut down on traffic or help more people get from point A to point B. "If it's individuals owning cars, you've not increased the capacity for getting people into urban corridors," Boland notes.

The environmental implications are also cloudy. A bunch of cars driving around with no people in them, will still produce emissions, either through the tailpipe or through the power plant that charges their batteries, until local utilities begin to rely fully on renewable energy sources.

Transitioning transit

What scenarios are smart planners pondering as we get ready to share the road with autonomous vehicles? 

Some cities — London, Milan and Stockholm — already use congestion pricing and similar disincentives to driving that seek to solve the congestion and air pollution that cars create, regardless of how they're driven. 

Elsewhere, transit agencies are considering automation schemes that might lead to buses and trains sans drivers. With labor being the biggest expense of running public transit systems, this could allow cities to expand transit routes and capacity more cost-effectively. "There are already driverless trains in Vancouver. Of course, if you tried to lay off thousands of bus drivers tomorrow" that would not fly, Boland says. "But if you let them retire out, it could work, and that would make transit more affordable."

Another, opposite scenario suggests that rather than complimenting public transit systems, SDVs might push them out. "One question that is being raised," Bhat says, "is 'Why would I need high speed rail if I can just get in my car, start my trip late at night and arrive next morning?'"

If humans can do things other than driving while we're inside vehicles, this could lead us to buy increasingly large vehicles and to move and live even further away from urban centers, a divergence from the "smart city" concept and global trend toward urbanization.

Taking this idea to another extreme, Bhat posits, one wonders about the stability of the real estate market. "Why would I need a home? I could create a mobile home instead. In the context of urban planning, it's all about location. The price of any property is dependent on where it is. Will that model completely get undone? Will [SDVs] increase the geographic footprint of our cities?"

It seems unlikely that cities will evolve into massive mobile home parks, but certainly many of the outcomes caused by the original "horseless carriage" were not expected either. 

"In 1910, no one could have known we would have huge freeways running through our cities, or that cars would bring about urban sprawl," Boland says. "I think Silicon Valley types have a tendency to focus on the positive. But they also have a tendency to downplay potential side effects," he adds, referencing the bullishness over driverless cars among Google and other tech giants.

Still, Bhat says SDVs are more likely to improve cities rather than handicap them. "The marketplace is more creative than we give it credit for. Departments of Transportation and infrastructure agencies will understand that [SDVs represent] an opportunity to come together. It's not an issue of if, but when."

Photo: Joseph Thornton/Flickr

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Mary Catherine O'Connor

Contributing Writer

Mary Catherine O'Connor has written for Outside, Fast Company, Wired.com, Smithsonian.com, Entrepreneur, Earth2Tech.com, Earth Island Journal and The Magazine. She is based in San Francisco. Follow her on Twitter. Disclosure