Breathe easy, New York. With fewer cars in Times Square the air there now has about half the pollution it did before.
Well, now we have numbers. For New York, at least. Back in 2009 Mayor Bloomberg prohibited vehicle traffic on Broadway between 42nd Street and 47th Street in Times Square to create a pedestrian plaza (video here). Now, the city's most recent Community Air Survey found that, "After the conversion to a pedestrian plaza, NO pollution levels in Times Square went down by 63 percent while, NO2 levels went down by 41 percent." Unlike N2O, which makes you laugh at Phish shows, NO2, or nitrogen dioxide, destroys your lungs and may cause Sudden Infant Death Syndrome. Nitric oxide (NO) isn't good for you either.
Sixty-three percent? Forty-one percent? Those are significant changes. I hope someone is running a study to track how overall pollution levels in the city correlate to various respiratory diseases so we can translate those air quality stats into public health stats.
Shutting down streets to cars to improve the air you breathe to stay alive. File it with the ideas that work.
Image from Flickr user Valerio_B