By Andrew BowenThe Daily Northwestern

Thirty bicyclists gathering in a public space would make any driver a little bit worried. In large groups like that, they could easily take over the streets.

Evanston bike riders did just that Friday. Evanston Critical Mass, a community bike ride held on the first Friday of every month, is a time for residents to promote alternative modes of transportation and to have fun.

“It’s a very healthy, fun sustainable form of transportation,” said Rebecca Harris, a Medill junior.

Harris started riding with Chicago Critical Mass during her freshman year, she said. The Evanston branch formed last May, with about 50 people showing up for the first ride.

The first Critical Mass began in San Francisco in 1992. Bicycle designer George Bliss coined the term after observing the flow of bicycle traffic in China. At busy intersections with no traffic signals, Chinese bikers would congregate to form a “critical mass,” at which point they could cross the intersection safely.

There are more than 400 Critical Mass rides around the world, but there is no organization to oversee them all.

Thirty people met in Evanston’s Fountain Square, at the intersection of Davis Street and Sherman and Orrington avenues in downtown Evanston – a typical turnout, said Vic Sholis, 62, from Glenview.

“It’s obviously smaller (than Chicago Critical Mass), so it’s a lot of fun,” he said.