Partial closures of 405 Freeway ahead of Carmageddon II to start

Just think of these freeway closures as dress rehearsals for the upcoming sequel to last summer’s transit drama known as Carmageddon.

Transportation officials will close portions of the 405 Freeway through the Sepulveda Pass over the next two weekends so that workers can prepare the north half of the Mulholland Bridge for the final phase of demolition. The work is in anticipation of what is billed as Carmageddon II — the full 10-mile closure of the 405, in both directions, between the 10 and the 101.

The first preparatory closure — of the southbound 405 between the 101 and Getty Center Drive — is scheduled to begin at 11 p.m. Saturday and end at 9 a.m. Sunday. The northbound 405 between Getty Center Drive and Ventura Boulevard will close at 11 p.m. the following Saturday and reopen at 9 a.m. Sept. 16.

The 53-hour full closure is slated to begin about 7 p.m. Sept. 28, when workers will start shutting down ramps along the route. Individual lanes will begin closing about 10 p.m., with the entire freeway off limits to drivers by midnight. The closure is expected to continue until 5 a.m. Oct. 1.

The work is part of the epic project to add a carpool lane through the Sepulveda Pass.

During the partial closures, the contractor will remove the supporting wood structures from the newly built south side of the bridge and adjust Mulholland Drive’s alignment and elevation to meet the bridge’s new approaches, the Metropolitan Transportation Authority and the California Department of Transportation said.

The unprecedented July 2011 full-freeway closure quickly came to be known, in advance, as Carmageddon. Officials predicted nightmarish traffic jams, but that scenario didn’t materialize because motorists either stayed home or otherwise heeded warnings to steer clear of the construction zone. It also helped that the contractor finished 17 hours ahead of schedule.

This year’s work is expected to require the full 53 hours because workers will be removing two sets of columns rather than one set, as was the case last year.

With all of the upcoming closures, transit officials once again are advising motorists to prepare for delays and seek alternate routes, such as Sepulveda Boulevard.

Picking a suitable weekend for Carmageddon II meant working around big dates such as the Sept. 24 start of the fall quarter at UCLA and the highly anticipated and logistically challenging transport of the Space Shuttle Endeavour to the California Science Center in Exposition Park, expected in October.

The multiyear, $1-billion effort to build a northbound carpool lane on the 405, along with redesigned flyover ramps at Wilshire Boulevard and other improvements, is running several months behind schedule. But officials have said they hope to make up time and substantially complete the project in 2013. Metro officials have said they are well aware that residents’ and commuters’ patience has worn thin.

Los Angeles County Supervisor Zev Yaroslavsky’s website features a quote from Mike Barbour, who heads the 405 project for Metro: “The project is pushing to get this job done as soon as possible so we can get out of everybody’s hair.”

martha.groves@latimes.com