Inspired by the pollution-fighting Ciclovías of Bogota, Colombia, from some 30 years ago, L.A.'s fourth annual CicLAvia creates a new vision of our city, one where bicycles fill major thoroughfares in and around downtown instead of cars. This year is the biggest event yet, with 10 miles of streets closed to only bike and pedestrian traffic. It's difficult to decide which is the best part, the exercise from spending a day cycling without fear of traffic, the sense of community from seeing how different a city looks when viewed up close or some intoxicating combination of both that makes this vision seem like it could be more than just an annual reality. 10 a.m. to 3 p.m. Sun. Free. See http://www.ciclavia.org for details about route maps and more.