The Orange County Transportation Authority (OCTA) and Security Paving Co. are currently expanding a stretch of California SR-55 that starts at the I-405 intersection in Irvine and runs 4.3 miles north to the junction with I-5.
The Costa Mesa Freeway (SR-55) is a vital link to other major freeway systems in Orange County, and the only freeway providing a direct north-south connection between Central Orange County and the coastal region. This section of SR-55, within the cities of Santa Ana, Tustin, and Irvine, California, is among the most heavily trafficked highways in the nation. According to OCTA, more than 260,000 vehicles use this stretch of highway every day. That number is expected to grow to nearly 275,000 vehicles by 2040.
Taking advantage of a nighttime closure, Security Paving crews perform the installation of an overhead sign structure using cranes and precision alignment to safely mount the signage.
Currently, this section of freeway has four regular lanes and one carpool lane in each direction, as well as merge lanes between some interchanges. The project is adding another regular lane and a carpool lane in each direction, as well as additional merge lanes on northbound SR-55 between interchanges at MacArthur Boulevard, Dyer Road, and Edinger Avenue. This will improve traffic flow, reduce travel time, and enhance safety by making merging easier.
The Security Paving crew places the rebar and formwork for an upcoming concrete pour in the lane channel construction of the project’s massive drainage system.
Additional scope of work includes reconstructing and widening four bridges, relocating or resizing adjacent neighborhood streets, the installation of new sound walls, and the construction of new drainage systems, including the 3,139-foot-long Lane Channel, which runs parallel to southbound SR-55 and provides regional flood control.
Security Paving Co. began executing the $506-million contract in August 2022, with completion scheduled for next year. According to Security Paving Field Engineer Frank Gower, more than 15,000 cubic yards of Jointed Plain Concrete Pavement will be placed by the time the project is completed.
The Security Paving crew marks the sawcut lines on the newly placed JPCP ramp.
The SR-55 Improvement Project has a long history. Environmental work started in 2014, with project design taking place in 2017. The Caltrans review started in 2021, with the awarding of the project to Security Paving in 2022 to kick off construction.
Staging the Work
OCTA describes the SR-55 work as a “multi-asset project,” since, in addition to its highway infrastructure, the right-of-way contains equipment and infrastructure for multiple utility pathways, from electric and gas to water and communications.
OCTA officials coordinated the complexities inherent in working on these varying assets, working, more or less, all at the same time. For example, the reconstruction of six ramps adjacent to the MacArthur Boulevard intersection was divided into phases in order to maintain traffic, since all the ramps could not be closed simultaneously.
Temporary shoring was built to stabilize the excavation and protect nearby structures during below-grade work.
Construction started along the outside portion of the roadway. This included bridge widenings and building retaining walls. When the walls were completed, drainage work got underway. Next came lighting and installing communication conduits. Finally, paving.
Reconstruction at four major freeway interchanges – MacArthur Boulevard, Dyer Road, Edinger Avenue, and McFadden Avenue – could occur at the same time because of the construction team’s detailed scheduling.
Handling the Traffic
Due to intense traffic volumes, project managers confronted a uniquely hazardous work site. Caltrans is overseeing work site safety, with support from OCTA. The Security Paving team implemented enhanced traffic control plans, which include K-rail barriers, dynamic message signs, and California Highway Patrol enforcement to discourage speeding through the construction areas. Because of the volume of traffic, lane closures were limited to nights and weekends, with drivers encouraged to use alternate routes.
Security Paving crews place the concrete for a brand new offramp.
A project at this scale bumps into the local street grid pretty quickly, and in metropolitan Southern California, there is not much room to spare. Significant reconstruction was required for about two miles of local streets, including improvements to intersections at Dyer Road and Edinger Avenue to improve merge and diverge points. This work involved grading, paving, signal upgrades, and adding auxiliary lanes to handle diverted traffic.
Equipment and Technology
Security Paving has largely used standard industry construction equipment on the SR-55 Improvement Project. The company set up a recycling plant to take delivery of the asphalt and concrete removed from the project site. The material is then transported to a crush yard where the asphalt and concrete are repurposed for use as aggregate base material, eliminating the need to transport old material to landfills, and making it easier to return the crushed base to be incorporated back into the roadway section.
Regarding new technology, the design engineer, HDR, has included the use of expanded polystyrene geofoam blocks (EPS) for lightweight backfill of two large retaining walls. EPS may be used where settlement is a concern. EPS blocks are lightweight with a density of four pounds per cubic foot, and this backfill method prevents settlement and avoids “uplifting” effects on neighboring properties, including housing structures, streets, sidewalks, and parking lots.
Crew carpenters install braces to stabilize the newly placed concrete girders.
Bridge construction posed some challenges, one of which was staging demolition of the existing bridge overhangs (the section of the bridge deck that cantilevers outward from the last main support beam), followed by reconstruction over live traffic. This was needed not just once, but at three of the new bridge sites, which entailed full street closures. Work on the fourth bridge involved coordination with the Southern California Railroad Authority (SCRRA/Metrolink), as construction took place over the Tustin tracks.
The Security Paving crew places the structural concrete onto the rebuilt Dyer Bridge.
Another challenge was building the footing for the bridges in locations near area hotels. Disruptive activities, like pile driving, needed to be rescheduled. Instead of occurring at night, as originally planned, that work was shifted to daytime hours.
Project Partners
- Owners: Orange County Transportation Authority and Caltrans
- Project Sponsor: Orange County Transportation Authority
- General Contractor: Security Paving, Inc.
- Construction Management: AECOM
- Designer/Engineer: HDR, Inc.
Big thanks and a tip of the hard hat go out to Security Paving Field Engineer Frank Gower for all of his generous contributions and photography for this story.