I spent 45 minutes stuck in 2am traffic last Friday and I was about losing my mind. I can’t imagine what LA drivers will be going through next week when the 405 closes down. I only had to drive in SoCal once and while it was not nearly as daunting as I had heard it would be, we just missed being caught behind a serious accident when traveling from LA to Santa Ana. When I finally turned off the news at 2am, drivers were STILL stuck on the freeway from rush hour.
Here’s a good article about the history about the 405:
http://www.latimes.com/news/local/la-me-405-history-20110714,0,633354.story
It seems like there should be some way to work on such a major artery without excessive impact, but what do I know. I can’t believe this is going to help California’s currently shaky economy
Ooh Something Shiny! 
Actually, if you think about it, closing the 405 for a weekend will cause much less disruption than working on it over a long period. The part that fried my brain is that they’re closing Sepulveda, too. That’s the street you take to avoid the mess on the 405!