Crosswatch is a smartphone-based system developed for providing real-time guidance to blind and visually impaired travelers at traffic intersections. Using the smartphone's built-in camera and other sensors, Crosswatch is designed to tell blind and visually impaired travelers what kind of traffic intersection they are near, how to align themselves properly to the crosswalk, and when the walk light or other traffic light indicates it is time to cross.
Click here for link to zip file containing Crosswatch code (open source) and documentation.