Can drivers and cyclists co-exit in Los Angeles?

It was a warm April morning in downtown Los Angeles, and there was not a car on the road. For five hours, the streets were commandeered by nearly 100,000 people on bicycles — old and young, wearing spandex and silly hats, dogs and babies perched on handlebar baskets — in a celebration that produced a sight that once would have seemed inconceivable in this city of cars.