Via Twitter (of course), Fischer said, "[The map] is paths from one geotagged tweet to the next by the same person, routed along the most heavily geotagged path in between." In a comment on Flickr, he clarified, "Keep in mind this is trying to be a map of travel from locations to other locations, not of individual tweets. The individual tweets are just to guide the paths. I think what you are seeing here is mostly a lot of travel between O'Hare and the Loop, not a particular tendency to tweet while driving on that route. (Also, the Edens is hardly represented here at all. Those two big routes to the north and northwest are Clark Street and Milwaukee Avenue."