From the venerable eyebeam reblog, a unique project called "Crossroads" as covered at turbulance.org.

In this project music is generated from the colours of cars which meet on the crossroad. As cars pass by they create impulses which carry the basic informations equal to music like tone and interval, rhytm, structure. This information is used as the source code for the music composition created in realtime.

I then tweaked it to read the color yellow, hoped to base it off taxi traffic going down 5th avenue. I found my cable was too short, and that was the end of that project. (boy, of all the half-ass excuses to abandon a project)