I split my time between two cities that have completely screwed up their traffic light systems, but in completely opposite ways. The village of Ann Arbor, Michigan seems to use only timed lights and no sensors. San Diego seems to have a sensor for every light with each one acting independently. The evidence is observational Ė each time Iím pissed off by the light behavior I try to figure out why it did what it did so maybe I could adapt and be less angry in the future. The evidence for these claims is strong (though I havenít confirmed these facts) and they will be assumed as premises for this post.