CabTrails – 2006

CabTrails visualizes the movement of a Yellow Cab in San Francisco. As part of the Cabspotting project, the data from the GPS receivers installed in the fleet of San Francisco Yellow cabs has been made available for creative use. The real-time and historical positions of each cab are available for artists to interpret.

CabTrails accelerates three days worth of a cab’s movements and shows its path through the city as it picks up and drops off passengers. Starting from a blank slate, the cab’s movements build up its own frenetic view of the city.

CabTrails applet (as of Jan 2007 the data from Yellow Cab can be somewhat erratic). CabStats data analysis used to diagnose the data problem with Yellow Cab.


Processing applet retrieves an XML feed containing the cab location data from the Cabspotting web service.


  • Java applet written using Processing
  • ProXML XML parsing library
  • PHP web proxy
  • Cabspotting cab location XML feed
  • Python and Matplotlib for data analysis

Exhibition / Press History