Carmageddon II (subtitle: “This time, it’s Mulholland”) came and went over the weekend, shutting down for repairs a long stretch of what NBC News calls “405 Freeway,” but what locals call “The 405.”

Traffic was flowing through the Sepulveda Pass early Monday after bridge work that began Saturday as part of the freeway widening project. No major traffic problems were reported during the weekend-long freeway closure, which allowed crews to demolish the north side of the bridge. …

California Highway Patrol officers called the closure a success, but said several people broke onto the closed freeway. Seven people were detained, including rollerbladers and skaters, the CHP said.

California, man.

Heading south on the 405.
Omar Omar

The bad news is that the freeway reopened. During Carmageddon I (subtitle: “We’re closing the highway for a while; please find alternate routes”), the impact on the region’s air quality was immediate and dramatic. From Curbed Los Angeles:

UCLA’s Institute of the Environment and Sustainability found something pretty amazing during Carmageddon I’s 10-mile shutdown of the 405 Freeway last year: “air quality near the shuttered portion improved within minutes, reaching levels 83 percent better than on comparable weekends” and air quality improved 75 percent in parts of Santa Monica and West LA near the 405/10 interchange; because of reduced traffic all over, the entire SoCal basin, from Ventura to Yucaipa, Long Beach to Santa Clarita, was a full 25 percent cleaner. One of the lead researchers says in a release that “The air was amazingly clean that weekend … Our measurements in Santa Monica were almost below what our instruments could detect, and the regional effect was significant.” But it didn’t last for long: “The effect was gone by the next week … We measured fresh emissions: pollutants that come directly from cars. It’s a very short-term effect.”

Last week, we noted the strong correlation between childhood asthma in LA and proximity to major roads. And the 405 is the major-est road in the area.

In other words, the ideal traffic pattern for the health of Los Angeles residents would look more like this:

Which is the plot of the upcoming thriller Carmageddon III: Return to Nature. It opens in the year 4238, after the second ape rebellion.