Critical Mass, a semi-regular activist event that asserts bicyclists’ right to ride in the streets and celebrates the bicycle as a form of transportation, originated in San Francisco in 1992.
One of the cities Critical Mass spread to early on was Portland. On Friday, September 24, 1993, about 100 cyclists showed up for the inaugural Portland ride (The Oregonian, 25 May 2003).
By the early 2000s Critical Mass had spread to more than 200 cities globally.
Participants and their Web sites variously describe it as an anarchistic, democratic, flier-driven “Xerocracy” that intentionally names no leaders. Longtimers say they think of the Mass as more of a free-flowing organism than as any sort of group, and that riders see it as a chance for pollution-free travel to reclaim auto-clogged public streets. When some drivers fume that the Massers come across as self-righteous jerks by running lights and blocking traffic, some Massers retort with the slogan, “We ARE traffic.”
Further reading on Critical Mass in Portland: