Sometimes, trying to make things better actually makes them worse. If only a few people use apps to evade traffic snarls, everything works, but as more and more drivers tap on navigation apps for the fastest route around the freeway crawl, they often slow things down. They create new congestion -- at freeway exits and on streets not designed for heavy traffic. Berkeley's Alexandre Bayen is working to devise policy and technologies that help app makers work collaboratively with city planners. (#33081)