It's been 13 years since the first “Commute Clot” brought together about 50 bicyclists at “PeeWee” Herman Plaza at the foot of Market Street in San Francisco. Within a few short months it had gained the moniker “Critical Mass” and the excitement and euphoria and sheer novelty of an “organized coincidence” that fills the streets with bicycles instead of cars was rapidly reproducing itself across the planet.

Now there are websites galore documenting Critical Masses in towns everywhere, from Australia to Italy, Chile to Canada. Of the more than 400 places where Critical Mass rides have taken place, hundreds continue to ride every month. In May 2005 an “Interplanetary Critical Mass” was held in Rome, Italy, drawing several thousand riders from around Italy and the world. On Earth Day this past April, 10,000 riders staged a “Critical Mass” in Budapest, Hungary. Hundreds of rides occupy the streets of US cities on the last Friday of each month, from big cities like Chicago and Los Angeles, to the smaller burgs in the hinterlands like Cincinnati, Ohio, Grand Rapids, Michigan, and Portland, Oregon. And of course thousands are still riding after all these years at the birthplace here in San Francisco.

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