Pop-up City and others have re-blogged a fun data viz project by Cooper Smith, taking trails from individual Nike+ runs and making some neat maps and animations. It seems obvious to say, but the maps don’t show the “entire city” going running, as the author suggests. Instead, we’re seeing the well-heeled — literally, people running with a fancy chip in their shoe that wirelessly connects to your iPod as you run. And the maps show clearly that those people aren’t running in most of Brooklyn, Queens or the Bronx. If we want to use passively collected data in the planning and operation of cities, we need to remember who’s collecting the data, and who is missing.

But if you’re looking for an interesting representation of where self-quantifying data-hungry runners live, you’re in luck.

(Special shout-out to Crown Heights, a black hole on the map).