In the future, 80 percent of American development will take place in just 10 percent of its land.
"This is a major change in how we build the country," said Chris Leinberger, president of LOCUS, a group of real estate professionals who advocate for walkable urban development.
He compared this shift to the proclamation that the frontier is closed, made by historian Frederick Jackson Turner in 1893
A report released Monday by the Center for Real Estate and Urban Analysis at George Washington University School of Business in conjunction with Smart Growth America ranked the 30 largest U.S. cities by how walkable they are -- a key figure that demonstrates how cities are shifting from the suburban sprawl of the past 60 years to the urban infill of the future.
The researchers, including Leinberger, first looked at Walkscore heat maps, focusing on areas that scored high. They then looked at areas with significant regional importance, meaning they have at least 1.4 million square feet of office space and more than 340,000 square feet of retail space. They combined these factors to determine areas they call "walkable urban places" or WalkUPs.
Researchers then tried to predict how these areas would grow in the future by looking at trend lines and pricing premiums in rent space, which indicate demand level. For example, demand around train stations in places like Washington, D.C. is so high commercial and residential renters can pay a premium of between 50 and 80 percent, said Emerick Corsi, president of Cleveland-based Forest City Enterprises Real Estate Services.
For now, these 10 cities have proved the most walkable, but that doesn't mean they'll stay that way for long.