Mapping the end of the road on the 405

A key part of the project, a new Skirball Drive onramp to the southbound 405, opened earlier this month.

With the massive 405 Project now two-thirds complete, officials have unveiled a staggered endgame schedule which calls for major portions of the project to wrap up this year while work on one troublesome segment continues into 2014.

The delay involves the project’s middle segment—chiefly in the area around Montana Avenue and Church Lane—where utility relocations and the necessity of shifting Sepulveda Boulevard have proved vastly more time-consuming than expected.

Overall, unforeseen utility relocation issues have not only eaten up valuable time but also have driven up the cost of building the project, according to a briefing presented this week to Metro’s Construction Committee.

Engineering challenges involving a single 12-foot-by-12-foot box encasing a storm drain under Sepulveda Boulevard were particularly problematic, project manager Mike Barbour told the committee. In addition, 16 retaining walls needed to be torn down and rebuilt because they were deemed to be structurally unsound.

Metro officials say that even with the unanticipated obstacles, the project’s “design-build” construction process, in which engineering takes place as work moves along, has saved hundreds of millions of dollars and seven years of building time.

As it stands now, virtually all of the utilities have now been relocated, and the project is on track to finish work on most major elements by year’s end—including the Wilshire flyover ramps and all three bridges that have been demolished and are being rebuilt as part of the project.

The heart of the undertaking is construction of a 10-mile northbound carpool lane on the 405 Freeway from the 10 to the 101. When completed, it will form part of a 100-mile carpool lane through Los Angeles and Orange Counties, believed to be the nation’s longest such stretch.

In addition to building the carpool lane and demolishing and reconstructing the Sunset, Skirball and Mulholland bridges, workers have realigned 28 on- and off-ramps, widened more than a dozen underpasses and constructed some 18 miles of retaining and sound walls.

The southernmost segment of the project, running from the 10 Freeway to Wilshire Boulevard, is expected to open by mid-year, while the north stretch is on target to finish by year’s end, Barbour said.

The sheer size and complexity of the project has made things difficult for those who live in the area, Barbour acknowledged. But the end is in sight.

“They’re getting through it,” he said in a recent interview. “We’re as frustrated as they are. It’s been a long, torturous job.”

Posted 2/21/13