A public transit bus carries a message to drivers to watch for... News PhotoBuilt Structure,Bus,California,Car,Carrying,City Of Los Angeles,Climate Change,Commuter,Cycling,DIY,Driver,Environmental Issues,Finance,Flag,Greenhouse Gas,Highway,History,Horizontal,Hydrocarbon,Message,Mineral,Nitrous Oxide,Occupation,On The Move,Pollution,Renovation,Road,Smog,Traffic,Transportation,Two Lane Highway,USAPhotographer Collection: Getty Images News 2013 Getty ImagesLOS ANGELES, CA - APRIL 25: A public transit bus carries a message to drivers to watch for bicyclists in all lanes, not just designated bike lanes, as it passes an American flag hung on the Los Angeles County Hall of Justice by workers renovating the historic structure on April 25, 2013 in Los Angeles, California. The nation's second largest city, Los Angeles, has again been ranked the worst in the nation for ozone pollution and fourth for particulates by the American Lung Association in it's annual air quality report card. Ozone is a component of smog that forms when sunlight reacts with hydrocarbon and nitrous oxide emissions. Particulates pollution includes substances like dust and soot. (Photo by David McNew/Getty Images)