Here is California it always amazed me how they manage to expand/rebuild the expressways here without actually shutting down the highways for more than overnight. Back in Michigan when I lived near Detroit I remember that they decided to do some major work on one of busiest expressways going in and out the city and they just up and closed it for 18 months. Here in SoCal, they'll completely rebuild a 20 mile stretch of freeway, adding lanes and replacing overpasses and never close it once Maybe a few overnights when they're taking down an old overpass, but never more then say 11:00pm to 5:00am. The only recent exception was when they took down one side of bridge where Mulholland Drive crosses the 405 above LA last July. They did that over a weekend and it was the biggest news event in the area since the OJ trial.
This is a timelapse video where the compressed 2 says into a minute and a half:
http://framework.latimes.com/2011/07/18/time-lapse-video-mulholland-drive-bridge-removal-during-carmageddon/

OCU