A few days ago I was biking home from Manhattan and felt an unusual sensation. I was riding in a river of bike traffic, like you sometimes do on a park loop or the Hudson River Greenway. But I was nowhere near the greenway. I was biking on Chrystie Street.

I don't ride on Chrystie Street during rush hour all that regularly, and people who do are probably used to this feeling. For me, it was new and exhilarating. I'm used to pulling up at a red light with five or six other people on bikes. This was different - a platoon of 20 or so people stacking up at intersections, then rolling down Chrystie Street in a steady stream of bikes extending several hundred feet.

The phrase "safety in numbers" no longer felt like an abstraction. I almost expected a "we are traffic" chant to spontaneously break out.