Los Angelenos are mostly dreading the return of “Carmageddon” this weekend, when a key section of one of our city’s main freeway arteries will once again be shut down for construction. But apparently we should be craving the respite from our city’s pervasive air pollution. Researchers at UCLA have just posted an analysis of the effect of the last similar closure on local air quality. From UCLA’s release (to which all credit is due, or censure, for the CarmaHeaven title):
UCLA researchers report that they measured air pollutants during last year’s Carmageddon (July 15–17) and found that when 10 miles of the 405 closed, air quality near the shuttered portion improved within minutes, reaching levels 83 percent better than on comparable weekends.Because traffic dipped all over Southern California that weekend, air quality also 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.
More from the LA Times here. I live close enough to the area of closure to hear freeway noise, so I’m particularly happy about improvements close to the source. But the significant improvements elsewhere in the region are also striking (and presumably due to a decline in car travel throughout the area).
Like these numbers too? This is a nice controlled experiment, courtesy of Caltrans and Metro, illustrating what the air quality benefits might be if we made serious moves toward an electric-vehicle fleet (& see Ethan’s post, and the joint UCLA/UC Berkeley report it references, for ways California should be supporting that move).