Evening rush hour on the Hollywood Freeway (Highway 101) in Los Angeles. (Joe Klamar/Agence France-Presse via Getty Images)

America’s love affair with driving seems to be cooling off, while our obsession with urban living is heating up.

The percentage of Americans holding driver’s licenses has fallen sharply over the past several decades, especially among the young. In 1983, more than 91 percent of 20-to-24-year-olds held a license. By 2014, that number had dropped to approximately 77 percent and shows little sign of recovering. Meanwhile, big cities are growing faster than the country as a whole. The Pew Research Center found that 48 percent of Americans would choose walkable urban areas over suburbs, a number that is expected to grow. How will these two trends collide?

Although cars have shaped American culture and infrastructure, concerns about sustainability, safety and space have spurred a wave of innovations ranging from electric vehicles to self-driving ones, and a boom in car-sharing services such as Uber and Lyft. Meanwhile, interest in alternative forms of transport is growing in both urban and suburban areas. More people used public transportation in 2014 than they have in any year in six decades, and major metro areas are beginning to increase their investment in public transit, from D.C.’s own much-delayed but still symbolic H Street streetcar line to a potential $4 billion dollar transit expansion in notoriously car-heavy Atlanta.

Nationally, President Obama recently signed legislation equalizing the tax breaks for commuters’ public transit and parking benefits, encouraging the use of public transportation as an alternative to private vehicles. Bicycle commuting has also grown 62 percent from 2000 to 2014, and bike shares in major cities have increased interest.

All these developments suggest that the city of the future may not revolve around private vehicle ownership. Many of these changes have been supported by advocates under the banner of “New Urbanism,” a movement that has been brewing in cities for the past two decades. New Urbanists emerged as critics of suburban sprawl, emphasizing environmentally friendly and walkable cities and borrowing urban development models before the rise of the automobile. Across the pond, other countries are already taking steps to move away from urban areas dominated by private vehicles. Oslo is the latest city to announce plans to make its downtown completely car-free by 2019, and at least six other European cities have similar goals.

Yet making this ideal realistic in the United States means addressing a host of challenges: The existing infrastructure of cities have been built for and shaped around private vehicles, and in many cities, efficient public transportation remains inaccessible to low-income and minority populations. Projects to install new infrastructure also often face opposition for their high costs and from those commuting to the city from the suburbs.

With the growing emphasis on walkable, transit-oriented and less congested metro areas, is it still possible that the city of the future might be car-free? What technologies are most likely to dominate such a landscape, and what would be the financial, social and governmental implications? Is there history that could offer insight into the future or explain how cars became so central in the first place?

Over the next few days, we’ll hear from:

J. H. Crawford, author and car-free city advocate,

Randal O’Toole, senior fellow at the Cato Institute,

Shivani Radhakrishnan, PhD candidate in philosophy at the Columbia University,

Donald Shoup, professor of urban planning at University of California, Los Angeles,

Jarrett Walker, consulting transit planner and author of Human Transit blog,

Aaron Renn, senior fellow at the Manhattan Institute for Policy Research and a contributing editor at City Journal,

Carlo Ratti, director of the Senseable City Lab at the Massachusetts Institute of Technology.