“In one way, cars kind of happened to cities,” said Brian T. Kenner, the former deputy mayor for planning and economic development for the District, who recently left his job with the city to work for Amazon.
“There were a lot of lessons learned. . . . We know autonomous vehicles are going to happen in the future — one question is how quickly — but we want to make sure we’re at least thinking about the impacts they could have on the built environment,” Kenner said.
For example, because driverless vehicles will drop off passengers and move on, prime real estate now consumed by vast parking lots and unsightly garages could be freed up for more housing, parks, public plazas and open space, planners say.
In Cincinnati and Los Angeles, some new parking garages have flat floors and higher ceilings so they can be easily converted into apartments or office space as the demand for parking dwindles.
Last year, Chandler, Ariz., became one of the first U.S. cities to rewrite its zoning code to facilitate autonomous vehicles. Developers may now qualify to build less parking — a major cost saving — if they provide curbside passenger loading zones with benches and trees for shade.
Chandler planning manager David De La Torre said the Phoenix suburb, where Waymo has tested autonomous vehicles since 2016, hopes to someday replace parking lots with more attractive options, such as open space and parks.
“This is an opportunity to make our city more beautiful by eliminating huge parking lots and doing something more aesthetically pleasing,” De La Torre said. “It’s an evolution from an auto-oriented society to a more pedestrian-oriented society.”
In Washington’s Maryland suburbs, planners in Montgomery County will try to predict the effects of autonomous vehicles on the local transportation network as they update the county’s 30-year general plan.
“We’re trying to be flexible with our thinking,” said David Anspacher, a transportation supervisor for the county’s planning department. “We know a change is coming, but until we actually see a big adoption of the technology, there’s a lot of debate about the changes it will bring.”
If thought out, planners say, autonomous vehicles could increase car-sharing, which would reduce traffic congestion and air pollution. Because the technology will allow these vehicles to travel closer together, they will take up less lane space. Planners say cities could use the extra space for bike lanes and wider sidewalks, making walking and biking safer and more appealing. In addition, by making it easier to forgo owning a car, living in cities and close-in suburbs would become more attractive and affordable, they say.
But some say driverless vehicles could also worsen those problems, particularly if they’re priced affordably enough to make them wildly popular and encourage solo driving. Another concern is the potential for what some planners have dubbed “sprawl on steroids.” A two-hour commute becomes less onerous if travelers can nap, watch a movie or hold a business meeting rather than fume behind the wheel.
Some also worry that driverless vehicles could undermine years of work to curb traffic-inducing sprawl by focusing development on transit. People who can catch a ride door-to-door might not want to walk to or wait for buses and trains, let alone pay premium rents to live or work near subway stations.
A ‘renaissance’ in urban design
Most experts predict widespread adoption of autonomous vehicles will take 20 to 30 years, depending on their safety record, affordability and the public’s willingness to cede control to computers. But urban planners who plot out communities decades in advance and architects who design buildings for the next 50 to 100 years have already begun to wrestle with critical questions: How much parking will autonomous vehicles require? Will most people own them or buy into a car-sharing service? How much more will people travel when they don’t have to drive?
Tim Chapin, dean of social sciences and public policy at Florida State University, said planners know the “built environment” tends to be “very sticky” and slow to change, especially in comparison with the pace of technology.
“I think autonomous vehicles are potentially a force for people-centered design,” said Chapin, who has written on the issue. “We can remake our cities and suburbs for humans rather than vehicles. I think there’s a real opportunity here — if we do it well.”
Andy Cohen, co-chief executive of Gensler, a San Francisco-based design firm, said he sees automated vehicles sparking a “renaissance” in urban design.
“People have been so focused on the technology part,” Cohen said. “But we see them as a way to create great spaces for people and not for cars. . . . We can now go back and redesign our cities for the future.”
While many planners say they are concerned about the prospect of “zombie cars” roaming the streets in search of passengers, adding to traffic, they’re thrilled with the prospect that driverless vehicles won’t need to park close to their users. That would allow garages to be moved to less expensive outlying or industrial areas, leaving city centers for pedestrians and cyclists. Cars could park behind strip malls, allowing suburban roads to be lined with grass and landscaping. Because autonomous vehicles can be packed together when parked — there’s no need to open a driver’s door — garages and lots would potentially eat up significantly less land.
Meanwhile, residents could reclaim driveways for bigger yards and exchange garages for more living area.
“We can build more dense urban places that look like cities before automobiles, before we had to warehouse all these cars,” said Grady Gammage Jr., a land-use attorney for developers in Phoenix.
Shaping the future
In Boston, where autonomous vehicles have been tested since 2016, a recent study by the World Economic Forum and the Boston Consulting Group found that self-driving vehicles will require about half of the city’s current parking. That space could be used for transit vehicles, protected bike lanes and other “human-focused” purposes, said Kris Carter, co-chair of the mayor’s office of new urban mechanics.
“You can imagine all the things that become available when we need half the space that we have for parking today,” Carter said.
So what happens to all the windowless garages beneath office and apartment buildings?
Cohen, the California architect, said his firm tells clients they can “future-proof” their buildings with massive pickup and drop-off zones and aboveground garages that can be easily converted to residential or office space.
“What will you do with all that dark space” underground? Cohen said. “There are only so many athletic clubs and data centers you can put in there.”
Bryant Foulger, a developer based in the District, said accommodating autonomous vehicles is “very much part of our thinking.” His company plans to expand pickup and drop-off areas around the former Discovery building in downtown Silver Spring, which his company recently bought.
Foulger said he’s also thinking about how door-to-door self-driving vehicles might eat into transit use — and the premium rents that developers can now charge near subway stations.
“Will tenants be willing to pay the higher price to be near a Metro station?” Foulger said. “That’s a really valid and big question.”
When the University of Maryland’s National Center for Smart Growth Research and Education recently modeled how the Washington-Baltimore region might grow, researchers cited residents’ use of autonomous vehicles as a key force.
Self-driving vehicles, they found, would cause residents to take more trips, use transit less and live farther out. Many of the additional trips, researchers said, would come from those who can’t drive, particularly children, the elderly and people with disabilities.
Whether that additional travel results in more traffic congestion, researchers have found, will depend heavily on how much residents share cars and how much road space is freed up from vehicles traveling closer together.
“People are speculating and running models, but no one knows how cheap autonomous vehicles will become and whether people will choose to reduce private ownership to some degree or be willing to share a vehicle,” said Uri Avin, a research professor at the center. “Everyone is guessing about future behavior and costs.”
Carter, of Boston, said he’s not as concerned as some planners about the potential for super sprawl because most people don’t like to be regularly confined for long trips.
“The critique we hear in Boston is autonomous vehicles might allow people to move to somewhere like Vermont and commute in every day,” Carter said. “I don’t think that’s true. . . . I think human nature historically suggests we don’t have a desire to do that.”
Even so, some planners are considering ways that governments could discourage such behavior, for example, via a per-mile tax to make driverless vehicle passengers feel and bear the costs of longer trips. Such a tax, supporters say, also might discourage empty vehicles from adding to traffic congestion by roaming streets in search of passengers.
Unless cities pay close attention to how self-driving cars will shape their futures, experts say, they could easily repeat, and exacerbate, mistakes of the past.
“What we didn’t do a century ago with the auto was think about the impacts on our landscape,” said Chapin, the Florida State University professor. “We’re smarter now, and we can think about what we want our autonomous vehicle landscape to look like.”