This Saturday may be the one rare day when bicyclists rule the road, at least in selected parts of 100 Chinese cities. Manuela Zonensein, who recently returned to Beijing to find Chinese going car-crazy, explains why:

A dozen years ago, my adolescent mind could hardly grasp China's reality. That was my first trip East, and I came away with important wisdom still with me at present. Dumplings are delicious. Clothes and sneakers are disgustingly expensive in New York. And the world might be less inclined toward conflict if bargaining were an art form permitted everywhere and pursued as enthusiastically as it is here.

But one thing I was entirely unable to comprehend in 1995 was this: how on earth did swells of bicyclists successfully navigate the tide of pedalling wheels along China's city streets? Unfortunately, I may have returned to Beijing a little too late to find out.

Vehicles now congest Beijing's concrete arteries, and bicyclists seem a beleaguered minority. Urban sprawl and fewer bike-friendly roads mean private cares are increasingly seen as a necessity, especially if one of Beijing's three subway lines is too far away or traffic makes bus travel cumbersome. Just 10 to 25 percent of residents in large Chinese cities rely on public transport. By contrast, in Beijing more than 1,000 new cars hit the streets daily. The city's motor vehicle numbers will swell by nearly a million to 3.5 million by the time of the 2008 Summer Olympics, according to Chinese government estimates.

As for the fine art of bike-riding, I just might have a fleeting chance to try my hand this Saturday, Sept. 22. That's when Beijing joins 100-plus Chinese cities to participate in World Car-Free Day, a United Nations-backed global campaign and part of the first China Urban Public Transportation Week. In the capital, at least in theory, cars will be prohibited by the Beijing Environmental Protection Bureau from navigating along select roads from 7 AM to 7 PM. Two of these no-car zones are bustling commercial districts: from Tianqiao Dajie to Zhushikou Dajie and from Wangfujing Dajie to Baminacao. The task shouldn't be too hard: Wangfujing is already a pedestrian-only shopping street. You can walk the short distances along these byways within ten minutes.

Still I wonder whether Beijing's cars-are-us mentality can be suppressed. With roots in last year's World Environment Day, China's inaugural "No Car Day" may have little long-term effect. The no-car campaign kicked off, well, actually, just last Sunday -- but I have yet to see a single sign, television announcement, or subway or bus plaque advertising the campaign. Mention the upcoming event to an informed citizen, and no one seems to know much if anything about it. And believe you me: if the government wanted us to know, we'd know.

As an honorary Beijinger, I'll continue consuming my jiaozi dumplings, purchasing cheap threads, and bargaining in department stores, bars and other inappropriate places. But I guess I'd better get used to competing for wheel-space with Beijing's buses and cars, not against fellow bikers. Meanwhile Saturday I'll be out there, pedaling and weaving as best I can.