Interactive Map Shows How Crowds Move Through NYC During Workday

NEW YORK — It's no secret that Manhattan is flooded with commuters, tourists and other visitors during the week. But just how many are there? Where do they go? And just how quiet does it get when they're gone?

Data wiz Justin Fung offers some answers to those questions with the Manhattan Population Explorer, an interactive website that illustrates the extreme fluctuations in the borough's density.

The tool presents a block-by-block breakdown of Manhattan's population for each hour in a typical late-spring week. The number of people in New York County almost doubles on workdays, but Fung's map shows where the growth is concentrated: Midtown and the Financial District

"Everybody knows that FiDi and Midtown kind of empties out," said Fung, a Los Angeles-based data visualization specialist. "But I didn’t know the hard numbers behind that — like, do people live here?"

Fung, 31, used a range of publicly available data to create the map, including the MTA's subway turnstile database and U.S. Census data. He also referred to a study of Manhattan's population dynamics from New York University's Wagner School of Public Service.

His website, put up last summer, shows just how much two of the city's biggest commerical centers swell with visitors on weekdays. The Financial District's daytime population quadruples at its peak, Fung found, while Midtown's balloons by a factor of 10.

Nearly a million people combined buzz around the areas during the workday, according to the site — but they host fewer than 80,000 residents. That hints at why someone coming out of the subway in those neighborhoods in the early morning might feel like they're in a "ghost town," as Fung put it.

But the map holds revelations for other neighborhoods, too. Morningside Heights, for instance, attracts people during the day despite a general uptown exodus, bolstered by the areas around Columbia University, the site says.

The city government makes troves of data public that aren't available for other cities, Fung said. That helped give him "a very high-definition idea of the population at the block-by-block level in New York City that actually couldn’t be done in other cities," he said.

The site grew out of a project Fung worked on for the city's Emergency Management Department while he was working on his master's degree at Columbia University. He and other students analyzed how long it would take to evacuate Manhattan in an emergency depending on the population and time of day.

The project yielded a web-based tool visualizing their findings that helped the agency evaluate what modes of transportation would work best for getting people out of different parts of the city, an NYC Emergency Management spokesperson said.

Fung said the Manhattan Population Explorer proves the potential data holds if it's put in the right hands. It doesn't take fancy tools to make good use of it, he said — just a good idea and the motivation to see it through.

"There’s a lot of people out there that are curious and creative and love working with data," Fung said. "If a government can be more transparent with this type of stuff they can see immediate benefits that cost them basically nothing."

(Lead image: Photo from Shutterstock)