California Department of Transportation (Caltrans) officials hope to bring improvements to the 60/91/215 interchange faster and more efficiently with the use of design-sequencing.
The innovative method is part of California’s Design Sequencing Pilot Program that allows the agency to advertise the project using a bid package with 100 percent of the project concept and scope, 30 percent of the design, a description of each project sequence as it relates to the overall project and all potential work items.
“Design sequencing is a mechanism and a process by which the Caltrans agency is able to deliver a project much quicker to the public,” Caltrans Spokesman Thomas Knox said.
The agency is partnered with the Riverside County Transportation Commission and the Federal Highway Administration, and general contractor Washington Group /Obayashi Corporation Joint Venture will complete the work.
The $317-million project includes 4 mi. (6.4 km) of HOV lanes and widened freeways on I-215, SR 60 and SR 91, major structural improvement at eight local interchanges, two flyover connector ramps between I-215/SR 60 and SR 91, a new truck bypass connector leading from southbound I-215 to eastbound SR 60 and new bridges at Linden, Iowa and Blaine. The work will require 261,400 tons (237,138 t) of asphalt concrete and 176,500 cu. yd. (134,944 cu m) of concrete. The 60/91/215 interchange served more than 332,000 vehicles in 2004.
“This corridor was built approximately 30 years ago so it’s time to replace it,” Knox said of the 60/91/215 Freeway Improvement Project, which spans a 7-mi. (11.3 km) route.
“The structures needed to be replaced. The old primary interchange between 60/91 and 215 freeways was designed so many years ago that it wasn’t designed to sustain the amount of traffic being placed on it on an every day basis now.”
Although Washington/Obayashi is experienced with design build projects, this is the Boise, ID-based company’s first time using design sequencing.
“It forces a lot of change into the project and you never know how many to anticipate when it is a design sequence like this,” said Washington/Obayashi Project Manager Kurt Pegg. “We’ve had a tremendous amount of change in this project where it is no longer the project that we bid. It is a completely different animal, so estimating resources has been very challenging, to put it mildly.”
Pegg said the project is approximately 40 percent complete and work currently includes paving, excavation for retaining walls and storm drains and more. Washington/Obayashi uses loaders, backhoes, scrapers, and cranes from manufactures like Volvo, John Deere, Caterpillar and others.
“The Linden and Iowa bridges are 100 percent complete with traffic running on them,” Pegg said. “That was an incentive portion of the project where if that was done by the end of last summer we received a million dollar bonus for that part of the work.”
The company has 290 employees working the site and is contracted with 32 subcontractors such as All American Asphalt, Anderson Drilling, RMD Rebar and Diversified Landscape to get the job done.
“Besides the plans and the designs, our biggest [challenge] is just scheduling the stages of construction and keeping the traffic moving through the project smoothly,” Pegg said. “Bringing the whole thing together is like building a puzzle.”
In 1999 legislators authorized the director of Caltrans to choose six projects for Phase I of the Design Sequencing Pilot Program. In 2000, they increased the number of projects to 12, although only 10 were filled before the sunset date including the 60/91/215 Interchange Improvement Project.
Seven of the pilot projects are complete and three are still under construction. According to a Caltrans memorandum to Chairs and Commissioners from Chief Financial Officer Cindy McKim dated Feb. 1, 2006:
“Of the 10 projects awarded during the Phase I Pilot Program, the range of estimated time savings varies from no savings to 18 months. Completed projects have an average time savings of four months. As data is collected and analyzed, it is anticipated that the department will be able to demonstrate greater time savings due to design-sequencing.”
Legislators approved Phase II of the program in 2004 and at least four projects have already been chosen. The program requires that a Peer Review Committee submit reports to the legislature to determine the benefits of design sequencing.
Caltrans also must provide a baseline cost comparison between design-sequencing and traditional contracts to the California Transportation Commission. The memorandum noted that comparison results are in the preliminary stages and “the Department will continue to collect data by which to compare the two delivery methods.” CEG