Infographic Of The Day: Could Twitter Help Us Create Smarter Transit Routes?

Eric Fischer used geotagged tweets to create maps of the most highly trafficked thoroughfares in major cities.


Traditional city maps visualize just one aspect of urban design–the city’s intended structure, full stop. But add in a layer that visualizes how people actually use the city, and then the map becomes much more interesting. Eric Fischer did exactly that when he used Twitter’s API to collect tens of thousands of geotagged tweets and map them onto the streets of New York, Chicago, and the San Francisco Bay area. The maps amount to something close to a desire path on a macro scale: The maps show where our buses and subways should be, if they conformed to the way we actually move and live.

[In this map of Chicago, Fischer notes that the curve heading southwest doesn’t conform to any transit line–so why should there be one?]

They are essentially inkblot visualizations of where the density of urban flow is highest. (Thicker black lines mean more people passing down that road, street, or mass transit line.) The statistical and mathematical methods used to generate the maps will be of interest to cartographic data nerds (I’m looking at you, Tim De Chant), but laypeople can appreciate the patterns that emerge. In one visualization of the Bay Area, Fischer notes that “Telegraph is the street most neglected by existing rapid transit infrastructure.”

[In the Bay Area, Fischer observes that BART, in focusing on downtown commuters, doesn’t do a very good job of serving the corridor between Berkeley and North Oakland.]

Fischer’s maps are yet another example of the kind of powerful information that networked, ubiquitous sensors can provide. The MTA in New York City is spending billions of dollars to expand its mass transit system; how might a map like Fischer’s inform decisions on where, when, and how to dig new subway lines? With regard to the Bay Area, Fischer notes that “BART does not do a very good job of serving the most promising corridor in Berkeley and North Oakland. … Needless to say, if this were to be constructed, it would have to be pretty much entirely in subway to avoid tearing down the neighborhoods it would intend to serve.”

[When you look at New York, the central spine of Broadway leaps out at you. But the other big spines are telling as well: They conform to subway lines. In New York, neighborhoods truly live and die by the subway.]

Commenters on Flickr are already beseeching Fischer to offer his maps as large format art prints. In the meantime, you can peruse the details of his maps in our slideshow.

About the author

John Pavlus is a writer and filmmaker focusing on science, tech, and design topics. His writing has appeared in Wired, New York, Scientific American, Technology Review, BBC Future, and other outlets