405 countdown
It will require an army of workers and the precision of a military operation - a 53-hour undertaking that will practically separate the San Fernando Valley from West Los Angeles for more than two days. Daily News.
Over the weekend of July15-18, work crews will dismantle a portion of the Mulholland Bridge over the 405 Freeway. The northbound side will be closed from the 10 to the 101 freeways, while southbound lanes will be shut down from the 101 to Getty Center Drive.
An estimated 500,000 motorists drive the freeway during those hours - 500,000 people who are now being urged to stay home that weekend and avoid even the alternate routes of Sepulveda Boulevard and the canyon roads to travel between the Valley and the Westside.

Los Angeles Daily News City Hall reporter 

This same shutdown will be repeated 12 months from now when the other side of the bridge is demolished.
This Second shutdown could have been avoided!
A new bridge was supposed to be built 200 feet south of the current bridge leaving the current one fully functional. Then and only then would the old bridge be removed and all four lanes could be demolished in only one weekend and not twice.
But a few vocal and connected factions, stopped that plan and we are left with suffering through two long weekends.
This issue is expanded upon in Zev Yaroslavsky's March newletter
http://zev.lacounty.gov/communities/westside/a-sharp-u-turn-on-mulholland