PLAN 87: Article
Mapping the Unmapped

Using Cell Phones and Social Media to Understand the City

Two recent projects at SA+P highlight the use of cellphones and social media for better understanding urban and economic dynamics. One of the projects mapped workers’ movements in Manhattan’s Garment District, revealing the continuing economic value of industrial clusters, and another mapped the informal transit system of Nairobi, revealing unanticipated structure in the apparent chaos. Both projects were conducted, in collaboration with others, by SA+P’s Civic Data Design Lab, directed by Sarah Williams.

For the New York study, recently published in PLoS One, Williams and the research team used the social networking app Foursquare to track in real-time the movements of fashion workers at apparel firms in the metropolitan area over a two-week period. By producing a minute-by-minute account of the industry’s inner workings, the effort shed light on the current debate as to whether industrial clusters such as the Garment District remain essential to urban economics.

Economic clusters have long been shown to offer businesses economies of scale and scope; the benefit of creative synergies; shared resources; up-to-the-minute awareness of industry innovations; and intimate knowledge of competitors’ efforts. But some have argued that the rise of telecommuting diminishes the need for physical proximity and that an industrial cluster like the Garment District — an area of prime real estate with protective zoning — should be relocated or even dispersed, especially given the decline of apparel manufacturing in the United States.

The research revealed, however, that 77 percent of all trips made by fashion designers across the region, and 80 percent of business-related trips, were logged within the boundaries of the Garment District, confirming the continuing importance of the district in conducting the industry’s business. And the study has larger implications: given the growing return of US manufacturing, the dynamics of industrial districts like this – and the importance of proximity in urban economics, in general – should be of particular interest for rebuilding American cities in decline, such as Detroit and Buffalo. Williams and her collaborator at the University of Southern California, Elizabeth Currid-Halkett, hope to apply the methods used in this study to other agglomeration economies, such as the tech industry.

The study in Nairobi focused on public transportation, an informal transit system consisting of buses called matatus that are licensed by the city but run by hundreds of private companies on routes that are vaguely based on a network from 30 years ago. Due to the fact that maps of the actual system have never been developed, residents find it hard to know how best to navigate the city and, more importantly, urban planners are limited in their ability to manage the system and model traffic flows.

To help people visualize the system, students from the University of Nairobi – partners in the research project – used their cell phones to gather data along all 130 routes in the network. The research revealed that the system is not as chaotic as it seems – there are numbered routes, there are regular stops, there is in fact a system that can be improved upon. The map reveals, for instance, that the network is heavily centralized, complicating congestion downtown, suggesting one way in which the system could be organized more efficiently.

The map of the system has been published in several of Nairobi’s major newspapers and downloadable versions have gone viral on Twitter, helping residents navigate the system more efficiently now. One student who worked on the project, in fact, realized for the first time that he could get across town by a better route.

These projects are just two of a groundswell of data visualization and mapping projects underway in the school. Some others include:

  • In architecture, John Fernandez is mapping the metabolism of cities and Christoph Reinhart is mapping the roofs of urban neighborhoods to determine best locations for solar panels.
  • In planning, Carlo Ratti is mapping air pollution in Hong Kong and Shenzhen, road-induced stress in US cities and the ways in which Singaporeans move through urban space.
  • At the Media Lab, Ethan Zuckerman is mapping how news stories spread throughout the culture, Sandy Pentland is mapping spending behavior in relation to social behavior, César Hildago is mapping the connections between countries and their products and Sep Kamvar is making 10,000 maps – 100 maps of 100 cities – to show a wide range of information never visualized in that way before.
  • More information on those efforts can be found online by searching the professors’ names.