At least you have a 3-week warning

It could be worse.

Coldwater Canyon is being closed starting March 23 for about 28 days.  Some commuters to UCLA may use Coldwater Canyon and will be directly affected.  But even for those who don't use that route, it means more traffic will be pushed to Sepulveda and to the 405.

From the Westwood-Century City Patch:

COLDWATER CANYON BOULEVARD CLOSURE
Begins March 23, 2013
8:30 a.m. to 7 p.m. Monday through Friday
8:30 a.m. to 6 p.m. on Saturday

Starting March 23, 2013, Coldwater will be completely closed to through traffic from Ventura Boulevard to Mulholland Drive for approximately 28 days. In anticipation of DWP construction, left turn lanes will be affected near Coldwater Canyon and Ventura Boulevard. Exact locations and times of closure will soon be announced. Outside of the construction hours, one northbound lane of Coldwater Canyon and one southbound lane will be open.
Crews and Councilmember Paul Krekorian's office will work with affected residents, schools, businesses and others to allow special local access during construction.

Full story at http://beverlyhills.patch.com/articles/latest-details-on-how-to-navigate-coldwater-canyon-geddon-shutdown