One of PPS's first major projects was adding benches to Rockefeller Center in New York to make it a more attractive as a place to gather.

Great public spaces resemble pornography, at least in the way the U.S. Supreme Court defines it: “You know it when you see it.”

Gazing upon alluring spots like the Old Town of Prague, Prospect Park in Brooklyn, or even the courthouse square in a small town, and you naturally think, “I want to hang out there!” You’re attracted to the place and want to be a part of it, watching the people pass by, soaking up the atmosphere.

While it’s easy to identify a great public space, it’s often quite difficult to create a new one today. Many projects setting out to establish a congenial spot for people to congregate — whether a park, shopping district, plaza, waterfront development, civic building, mall, or revitalized downtown — wind up as miserable failures that  feel hostile to very idea of people enjoying themselves there.

William H. Whyte, a noted journalist and mentor to PPS, once observed, “It’s hard to create a place that will not attract people. What’s remarkable is how often this has been accomplished.”

One reason so few truly good public places have been built in recent decades is that urban planning today is pinpointed on specific outcomes— number of vehicles moved on the street per hour, sales revenue per square foot of retail space, or even unimpeachably admirable aims like the number of affordable housing units built. And these myopic goals are ardently pursued at the expense of creating a place that works for the public as a whole.

Development projects today are considered a success to the extent that cars move fast or  cash registers go ka-ching . But they often fail at the equally important mission of creating lively places where people can feel happy hanging out with their fellow citizens. It’s another example of the tragedy of the commons. The value of a public place to the whole community is trumped by the narrow interests of retailers, motorists, etc.

It doesn’t have to be that way. Throughout the world you can find brilliant examples of recently built public spaces that also succeed marvelously as shopping districts (a number of  new developments in already lively downtowns), transportation corridors ( Portland’s new Pearl District trolley line) or affordable housing (public housing projects like Park DuValle in Louisville and Diggs Town in Norfolk, Virginia, that have been transformed into thriving communities).

All that’s needed is a plan that takes into account a place’s broader role as a public spaces alongside other aims.