In just a few years, driverless cars have gone from a far-off, futuristic vision to a near certainty. Carmakers and tech companies are racing to develop road-ready vehicles that can self-navigate our streets; Google recently claimed that its fleet of self-driving vehicles logs 3 million simulated miles every day. Of course, that certainty comes with a fairly massive asterisk: widespread adoption, technological hurdles, and legal frameworks need to be ironed out, and of course, there’s no street-legal robotic car on sale to the public just yet. But the massive investment and potential size of the market (potentially worth $42 billion, according to Boston Consulting Group) means they’re on their way, in one form or another.

This means huge shifts in our daily commute, but it also has the potential to dramatically reshape our cities. Cars—their size, reach, and environmental impact—have been a huge factor in urban planning and development over the last century. A world where driverless cars are prevalent, and shared vehicle ownership is the norm, offers a chance to rethink and reconsider the design of our urban environment. Curbed spoke with five transportation and urban design experts and asked them to speculate on how this potential future of transportation, arriving soon under its own guidance, may reshape the cities we live in.

Goodbye, Parking Lots (and Parked Cars)

Alain Kornhauser, Professor at Princeton: "The biggest impact is going to be on parking. We aren’t going to need it, definitely not in the places we have it now. Having parking wedded or close to where people spend time, that’s going to be a thing of the past. If I go to a football game, my car doesn’t need to stay with me. If I’m at the office, it doesn’t need to be there. The current shopping center with the sea of parking around it, that’s dead."

Dr. Kara Kockelman, University of Texas at Austin: "It really depends on how many people let go of personal vehicle ownership. I think we’d lose 50 percent of parking demand. If everyone did it, you could get rid of 7 out of 8 cars on the road, so you’d need an eighth of the spots."

Carlo Ratti, Director, MIT Senseable City Laboratory: "An average vehicle in the US is parked for a staggering 95 percent of the time. Car sharing is already reducing the need for parking spaces: it has been estimated that every shared car removes between 10 and 30 privately owned cars from the street. Self-driving vehicles will reinforce this trend and promise to have a dramatic impact on urban life, because they will blur the distinction between private and public modes of transportation. "Your" car could give you a lift to work in the morning and then, rather than sitting idle in a parking lot, give a lift to someone else in your family—or, for that matter, to anyone else in your neighborhood, social-media community, or city."

Alain Kornhauser: "If you’re on Michigan Avenue in Chicago, there’s great stuff there. But go a half a block away, and it's all parking lots. The block behind Michigan Avenue is basically a parking garage for those going to Michigan Avenue. With autonomous cars, you won’t need to provide that parking, and suddenly, all this land opens up. There is so much to do with this kind of space: we need a lot of creative people thinking about what this means."

Gerry Tierney, Senior Project Architect, Perkins + Will: "The salient feature here about autonomous vehicles and driverless cars is that it allows for a shared vehicle ownership model. We did a study and presentation for SPUR (a San Francisco urban research and city planning non-profit) and looked at the efficiencies driverless cars bring to the road, which could be up to 400 percent less vehicle traffic. Let’s be conservative and say using them would bring a 200 percent increase in efficiency. If you applied this to all of San Francisco, and created a road diet that reduced roadways to reflect this decrease, you’d gain the equivalent of one-and -a-quarter Golden Gate Parks worth of space. That’s a lot of public space.

Carlo Ratti: "From an architectural point of view, the city of tomorrow won't look fundamentally different from the city of today—just as ancient Rome doesn't differ all that much from the cities we're familiar with today. What will change, however, is the way we experience it—especially from the point of view of traveling."

Gerry Tierney: "In this environment, you don’t need to park your car, it’ll park by itself, so you can think about recapturing the space from the front of one building to the front of another building. It does become a pedestrian-dominated environment, where these vehicles would need to take a more subsidiary role. We would see a huge increase in the amount of space given up to the public realm and a huge increase in the width of sidewalks, bike lanes, and space for any other kind of alternate transportation."

San Francisco Trolley Ride - 1906 from mead video on Vimeo.

Gerry Tierney: "I’ve cited this example before: there’s a video taken in San Francisco in 1906 before the earthquake, a journey down Market Street. Somebody put a camera in the front of a street car, heading towards the Ferry Building. People often look at that in terms of the architecture, and how the city looked back then. But really, when I look at it, it shows how people interacted with the public realm before the advent of the car. The film shows people weaving between horses, carts, and cable cars. There are a few cars on the road, but it looks like Mr Toad’s Wild Ride, weaving all over the place. The instructive thing is seeing people walk without being conditioned to walk under the front of buildings. They just use the space whatever way they want. Up until about a 100 years ago, that was how everyone experienced the city. Only recently have we been trained to walk dutifully along a little sidewalk, waiting for the man on the sign to turn from white to red to allow us to cross. This will allow us to go back to how we always have used the space between buildings, as a really and truly open public realm. There’s a real back to the future part about this that's really exciting to me."

Public Transit: Strengthened or Threatened?

Paul Lewis, Vice President of Policy, Eno Center for Transportation: "I think it might help public transport in many ways. The first, early adopters could very well be a fleet owner like a transit agency. If the economics of driverless buses work out, they may be able to save costs and get more buses on the road. The transportation system in dense, urban areas really can’t work without public transit, or vehicles that can carry dozens or hundreds of vehicles. There’s just not the roadway capacity for everyone to have their own vehicle."

Alain Kornhauser: "In the simulations I’ve done in New Jersey, with the ability to go to Princeton Junction or another train station without worrying about parking your car, autonomous vehicles increases ridership on NJ Rail by a factor of five. Instead of having trains run every 30 minutes, you’ll need them every 5 minutes."

Dr. Kara Kockelman: "One of the reasons people don’t use bikes is that they’re scared of cars. With everyone being so multimodal, shared bikes are going to be pretty important."

Preventing a Winners and Losers Approach to Transportation

Gerry Tierney: "We have to start thinking about unintended consequences. Where will the garages be where we store all these cars? We have to be careful that we don’t start locating these in communities where the land values are low. The wealthy will have a bucolic public realm, where the poor areas will be besieged by autonomous vehicles like a swarm of flies. We have to be conscious and make sure we don’t let this happen. Right now, this whole brave new world is presented with 20- and 30-somethings enabled, wired up, and dialed in. They’re calling their Ubers and having a grand old time, and then down the corner, the cleaning lady is standing on the corner waiting for the bus that isn’t coming. We just can’t have that happen. If we’re moving toward this autonomous, decentralized transit system, we need to make sure that it’s accessible to everybody, that there’s a social equity concept in the design."

Will Cities Become Denser, or More Spread Out?

Alain Kornhauser: "What happens to the Levittowns of the world? To me, the implications is, if you look at residential density of desirable living units, I think we revert to row houses, like the ‘20s. It’s not necessarily going to be high-rise, like a Beijing."

Paul Lewis: "If you have policies that encourage sprawl and single family homes, and that lifestyle continues to be affordable, that’s the result you get. It’s about how we shape our policies."

Gerry Tierney: "The argument has been put forward that now, with this technology, people can move anywhere around the Bay Area. People argue that more people will live further away and live in the suburbs. People fundamentally choose to live where they want to live. I think by and large we’re seeing a situation now where people want to live in a city, and not rely on transit infrastructure, autonomous or not. Doesn’t matter how whiz bang this technology is. I think a lot of people will want to live in a neighborhood downtown for various reasons that go beyond transit."

Dr. Kara Kockelman: "A big concern that I have for cities, states and regions is excessive travel. I think there will be rules about sending out your vehicle empty, or how many empty rides a fleet operator can send out. In simulations we've run for Austin, we constantly see 8 percent or less vehicle miles traveled with empty vehicles. If people share, it’ll reduce empty VMTs. But if the cars allow people to feel like they can go farther, easier, that’s a big concern. I think we’ll need a credit based congestion pricing model."

Paul Lewis: "We forget that to the point where a car can get us fro point A to B by itself is a long way away. In the short run, we’re seeing cars run by themselves in a controlled environment, on a highway and freeway. Self driving is already starting with lane control and adaptive cruise control. Making long commutes easier could increase the number of people taking cars to work because it’s easy, then there would be more people needing parking spaces."