Carmageddon Improved Los Angeles Air Quality During 2011 Freeway Closure, Study Shows

By James Gerken, The Huffington Post

On the eve of "Carmageddon II," researchers from the University of California, Los Angeles revealed that last year's July 15-17 closure of Interstate 405 resulted in significant air quality improvements in the vicinity of the freeway.
...

The researchers also found that with an overall decrease in traffic across the Los Angeles area during the Carmageddon weekend, "air quality ... improved 75 percent in parts of West Los Angeles and Santa Monica and an average of 25 percent regionally — from Ventura to Yucaipa, and Long Beach to Santa Clarita."
...

Yet the air quality improvements disappeared with the return of heavier traffic the next week....

<a href="http://www.huffingtonpost.com/2012/09/29/carmageddon-los-angeles-air-quality_n_1925523.html?utm_hp_ref=green">http://www.huffingtonpost.com/2012/09/29/carmageddon-los-angeles-air-quality_n_1925523.html?utm_hp_ref=green</a>;