LA Times explains how a broken elbow led to a revolution in cycling in LA:

On July 17, 2010, after a P90X workout, Los Angeles Mayor Antonio Villaraigosa and his police bodyguard began riding mountain bikes west in the bike lane on Venice Boulevard. About 6:30 p.m., heading toward La Cienega Boulevard, they were cut off by a taxi cab. Villaraigosa flipped over the handlebars. His elbow shattered on the asphalt. Two days later, with his arm in a cast, he told his staff, “Let’s use this as a teachable moment” — and for good reason. He and the city had a lot to learn about how to make bikes safer to ride and how to integrate them into the transportation system.

L.A. biking’s big break – Los Angeles Times