Many of the city’s parks and plazas are in far better shape today than they were 10 years ago. The pedestrianization of Times Square was the flagship, but the NYC Plaza program that began under the administration of Mayor Michael R. Bloomberg (and which our architectural consultancy helped initiate) has created more than 50 new plazas, in all five boroughs. Along Broadway alone, five sites opened up an area equivalent in size to Bryant Park — space that is free for everyone to enjoy. Like bike lanes, these innovations attracted some criticism at first, but today they have largely been accepted.

Before the changes, Times Square had no square — even though, for decades, pedestrians vastly outnumbered motorists passing through the area: 90 percent of the users were being squished into just over 10 percent of the area. After the changes, the rate of injuries went down (for pedestrians, but even more so for motorists), traffic flow in Midtown improved, and local businesses thrived — a fact reflected in steeply rising values of retail space.

It is a measure of that success that Times Square is now such a bustling place, walked by up to 480,000 people — tourists and locals — every day. The plaza program has made New York a leader in the international movement to make cities more people-friendly, while remaining pragmatic about cars. Mr. de Blasio has carried through his election campaign theme of a “tale of two cities” into the OneNYC plan, an equitable vision for ensuring access for all residents to everything New York has to offer.

That so many people are clamoring to spend time in Times Square means the city faces a new challenge of managing this vitality — one that’s very recognizable from the experience of cities across the world. Here in Copenhagen, the process has been evolving for more than five decades since the city first pedestrianized a street in 1962. Urban space develops organically and in sync with a city’s communities if it’s nurtured properly, but we’ve learned that this requires cities to keep reviewing how that space is designed and regulated.

There must be mechanisms for maintaining a balance of activities, to avoid one particular group of users, like panhandling performers, dominating. Sometimes, that means regulating activities that are a nuisance or offensive. But imposing conditions or constraints is only part of the solution.