From Mashable Tech.
He plots out the motion of New Yorkers using public tweets on Twitter with geotags from May 2011 until January.
The project lays out around 10,000 geotagged tweets and 30,000 point-to-point trips in cities like New York City to plot the flow of people in terms of favored paths. In his map of NYC, seen above, there is a huge ink blot lining Broadway; as we’ve long suspected, it looks like the busy avenue is the backbone of the city.
Using a base map from OpenStreetMap, he drew out transit paths using Tweets. Movements are indicated on the geolocation of a Tweet, with an individual’s start point marked with one geotagged Tweet and ending with the next geotagged Tweet. This is what creates a mass of traffic routes.
“If you just draw lines from the beginning to the ending of each trip, you get a big mess, so the challenge is to come up with more plausible routes in between,” Fischer told Mashable. “That is where the 10,000 individual geotags come in, the most plausible routes are ones that pass closely through places that other people have been known to go.”
Fischer used Dijkstra’s Algorithm to calculate what exactly to map out. For those of who haven’t thought about math since high school algebra, that’s an equation that maps out the shortest path between two points on a graph. For this project, the equation pointed to the relevant paths to map out a city’s most dense corridors.
This might be of use for our mobility project with our space.