After July of this year the entire 72.2-mi. (116 km) stretch of Interstate 405 South and nearly all of I-405 North, which originates in Los Angeles County and ends in Orange County, will feature a high occupancy vehicle (HOV) lane, as Balfour Beatty Infrastructure Inc. is nearing completion of a $167 million HOV lane project along a portion of the interstate.
Started in late 2004, the project has involved widening an approximately 6 mi. (9.6 km) span of I-405, from Interstate 10 to State Route 90, by one HOV lane in each direction, performing bridge widening and improvements, and constructing reinforced concrete retaining walls, according to Heath Williams, project manager of Balfour Beatty.
Serving the Los Angeles International Airport and the Port of Long Beach, I-405 is considered by Caltrans District 7 to be “unquestionably one of the busiest freeways in the entire region,” as peak traffic hour volume is anticipated to increase to 12,100 southbound and 11,700 northbound vehicles per hour in the coming years.
By constructing a HOV lane that spans the entire I-405 South and nearly all of I-405 North, Caltrans is hoping to encourage commuters to rideshare, thus relieving traffic congestion.
The lowest qualified bidder for the I-405 HOV lane project, Balfour Beatty constructed the job in three segments: from SR-90 to Braddock Drive; from Braddock Drive to the Venice Boulevard/Matteson Avenue off/on ramps; and from Venice/Matteson to I-10.
Each segment included lane widening, retaining wall, bridge and various city street work.
“Essentially the work was performed from the outside in, bridge work included,” Williams said, adding the project required moving traffic initially toward the median, to construct the outside, and then moving traffic to the outside to construct the median.
The roadway section of the project included large fill areas, which required retaining walls to hold in the fill, and cut sections that required retaining walls to hold back the existing material on the outside.
The construction of the retaining walls between Venice Blvd and the Palms Bridge represented a project challenge, as these walls were in an unusual cut section
“It took a lot of time to design the shoring system and to work around all of the bracing/raker system required to support the buildings above [the retaining walls],” Williams said.
A key piece of equipment during roadway construction was the Gomaco Commander III GT6300 paver, which was used for concrete paving and for slip forming of the Type 60 concrete barriers.
Widening work was conducted on 11 multi-span concrete box girder bridges and one steel plate girder bridge over the Westwood flood control channel, Williams said, adding Balfour Beatty also replaced the 212-ft. (64.6 m) long Palms Overcrossing bridge and widened a precast girder bridge at Venice Boulevard.
Besides the Gomaco Commander, other equipment utilized for roadway and bridge work included: Cat 330CL excavator; Cat 966 loader; Cat 446 backhoes; Cat 325 excavator; Cat 140H motorgrader; two, 40 ton Terex cranes; Skytrack forklift; JLG manlifts; Bobcat T 190; two John Deere 210LE’s, and John Deere 644G, Williams said, adding Balfour Beatty owned the majority of the equipment but did rent some additional items.
During bridge work, Ballona Creek posed some challenges, as construction crews had to build a platform to work from since they were not allowed to go into the creek bed.
In addition to interstate widening and bridge work, the project also has included various on/off ramp and city street work.
A significant amount of work occurred around Culver Boulevard, as the northbound Sawtelle off-ramp has been closed and the Culver Boulevard on-ramp is now an off-ramp.
Additionally Culver Boulevard has been realigned between Sawtelle Boulevard and Sepulveda Boulevard, and a northbound freeway off-ramp leading directly to Culver Boulevard has been constructed.
Relocation of bike path and pedestrian walkway to the northern section of Culver Boulevard also has occurred.
Other city street work included construction of a frontage road that connects Sawtelle Boulevard to Braddock Drive west of I-405.
In total, approximately 180,500 cu. yds. (138,000 cu m) of roadway excavation and 146,500 cu. yds. (112,000 cu m) of structural excavation were used for the project.
Other materials used included 41,200 cu. yds. (31,500 cu m) of Portland cement concrete pavement, 34,680 sq. yds. (29,000 sq m) of sound walls, 66,138 tons (60,000 t) of asphalt concrete, 5,940 yds. (6,500 m) of cast in drilled holes pile; 9,300 yds. (8,500 m) of concrete barrier; and 6.1 million lbs. (2.8 million kg) of reinforcing steel.
With different portions of the project occurring simultaneously, as many as 100 craft employees, during either day or night, were onsite during construction, Williams said.
During the entire construction process, Balfour Beatty was required to maintain four to five lanes of traffic throughout different sections.
“Occasionally we were required to close the freeway completely to install large freeway over head signs and traffic was diverted to city streets,” Williams said.
“This has been a complicated project,” said Judy Gish, public affairs officer for Caltrans District 7, adding this project included more associated city street work than other HOV lane projects within the district.
Because of the challenges associated with roadway and bridge work, as well as weather delays and the requirement to keep nearly all existing lanes open to traffic at all times, Caltrans previously extended the contract time of the project by 263 working days.
When this project reaches completion in July 2009, Gish said the next work along I-405 would involve the construction a HOV lane on the northbound side of the interstate, between I-10 and Highway 101.
Caltrans is hoping for a project start date of April 2010.
Subcontractors included: High Light Electric, Reycon, ACL, Coral Construction, Jesowski and Markel, Crown Fence, Sterndahl Enterprises, JD Jimenez Construction, P & D Landscape, Superior Gunite, Cemex Concrete, United Steel Placers, AC Dike Company, Avar Construction, Ortiz Asphalt Paving, Pavement Recycling Systems, Penhall Company, Statewide Safety and Signs, Anderson Drilling and Shoring Engineers. CEG