Carmageddon not just good for air quality, it's great

The biggest winners in Carmageddon are those people who live on the Westside. Not only did the 405 freeway closure last year make traffic disappear and stop the perennial roar of tires on pavement that blankets the area, it turns out that the drop in air pollution was dramatic. UCLA researchers say in a study today that the benefits began as soon as the freeway closed, and extended for miles around. Since traffic fell everywhere in Southern California, due to the changes in driving behavior brought about by all the warnings, the whole region felt an effect.

The benefits, of course, vanished as soon as the traffic returned. From the UCLA Newsroom story:

While the researchers expected cleaner air, they didn't expect the improvement to be so dramatic. "The air was amazingly clean that weekend," Paulson said. "Our measurements in Santa Monica were almost below what our instruments could detect, and the regional effect was significant. It was a really eye-opening glimpse of what the future could be like if we can move away from combustion engines." The research gives a peek at what the air would look like in a healthier Los Angeles with a vast majority of hybrid and electric vehicles and shows how quickly less driving can improve key measures of air quality. But to get a regional effect, the researchers said, you need a regional drop in traffic, like what Los Angeles saw during the first Carmageddon — and it doesn't last if traffic returns. "The effect was gone by the next week," Paulson said. "We measured fresh emissions: pollutants that come directly from cars. It's a very short-term effect."

With all the other research showing that the particles flying off freeways like the 405 are among the most dangerous air pollutants we have in Los Angeles, it's an eye-opener.

Also from UCLA, I spoke with Brian Taylor of the UCLA Transportation Institute in May about the lessons learned from Carmageddon I — basically what happened to all the traffic (and transit ridership, which went down too) and what's likely to happen during Carmageddon II. "It caused a dramatic behavioral change, more than was needed," he said of the warnings last summer. You can skip to his Carmageddon comments at this link.

The conversation covered a bunch of other local transportation issues, including the Expo Line, the Wilshire subway and Westside traffic. You can watch the whole thing below: