Caltrans photo
The California Department of Transportation is on schedule to complete construction on the Interstate 5)/State Route 56 Interchange Project in San Diego by the summer.
The article below originally appeared in and is posted with permission from:
https://www.constructionequipmentguide.com
The California Department of Transportation (Caltrans) is on schedule to complete construction on the Interstate 5)/State Route 56 Interchange Project in San Diego by the summer.
The project will help ease traffic congestion by adding high occupancy vehicle (HOV) lanes as part of a two-phase plan that will eventually result in a direct connector built from westbound SR 56 to northbound I-5.
Federal, regional San Diego Association of Governments (SANDAG) TransNet sales tax, city of San Diego developer impact fees and Private Local Partnership Program (P3) funds provided the $22.5 million for phase one. Phase two remains unfunded.
Phase one is well undeway and involves constructing an HOV operational lane in each direction on SR 56 between El Camino Real and just before Carmel Valley Road. The new HOV lanes will stretch for 3 mi.east of I-5. The job entails paving a previously vegetated median to make room for one new lane in each direction.
"This area was built without a westbound 56 to northbound 5 connector. But before we do that, we need to get the road prepared. Part of that is putting in these HOV lanes to loosen up the bottleneck and prepare for this other connector that will eventually go in," said Steve McMillan, Caltrans resident engineer. "These HOV lanes are also going to be used as transit lanes. That was a big proponent for the city of San Diego to approve this project."
Work began in January 2024 on these efforts that are part of a future transit blueprint approved in the 2021 San Diego Regional Transportation Plan addressing traffic congestion, community resources and other area concerns. It used community feedback and data analysis to implement a transformative transportation system in the city with a focus on innovation, sustainability and growth management.
The prime contractor on phase one, Granite Construction Co., is on schedule to meet deadlines, due to weekly meetings with Caltrans to review a three-week look ahead and constant communication between teams given the multiple parties involved. The contractors were selected for the project based on the most competitive bids from a pool of qualified candidates.
Other contractors involved include The JV Land Clearing Co. for clearing and grubbing; Southwest V-Ditch Inc. for slope paving (rock cobble); Alcorn Fence Co. for chain link fences, guardrails and treated wood waste; Ferreira Coastal Construction Co. for overhead signs and sign foundation concrete pile; SoCal Traffic Inc. for traffic control; Cooper Engineering Inc. for concrete barriers; Fortte Construction Inc. for electrical lighting systems and traffic monitoring stations; BC Traffic Specialist for pavement striping, markings and thermoplastic; Griffith Co. for project landscaping; and Tyler Reinforcing Steel Inc. for installing reinforcing steel.
Parts of the project that are complete include the hot mix asphalt (HMA) pavement and portions of the roadway that are jointed plain concrete pavement.
Crews are saw cutting the pavement. They're prepping for the concrete median barrier and bringing drainage inlets and electrical boxes up to grade. Then crews will finish overhead sign structures and pedestals before switching to stage two toward the end of the year.
Landscaping is scheduled as well.
"This job has some planting in it. We will have a one-year plant establishment during the period where the irrigation system is in place and the planting of bioswales along the sides of the highway [is] for trapping the initial runoff during a storm from the freeway," McMillan said. "The contractor is responsible for maintaining the plants and irrigation, including fertilizer applications, weeding and replacing any plantings that die within that year."
McMillan shared that an innovation of the project was the use of a Value Engineering Cost Proposal (VECP) that used a geogrid, allowing for several efficiencies. Approximately 24,400 sq. yds. of the material was used. The total savings amounted to $600,000.
"Granite Construction offered a different way to build the structural section that would be cost saving but with the same results, lifespan and usage achieved. It was a biaxial geogrid that helped reduce the structural section by almost half," McMillan said. "Since the reinforced composite plastic locks into the soil to stabilize, it helps distribute the load over a wider area so as much structural section to support the road above [typically a class 2 base] isn't required. Additionally, not having to take as much subgrade out of the project reduced truck hauling."
Other materials included 9,300 cu. yds. Of Class 2 aggregate base , 630 cu. yds. of jointed plain concrete pavement and 14,800 tons of hot mix asphalt (rubberized and Type A).
Equipment for the project included track dozers, excavators, dump trucks, a water truck, HMA lay down machine, steel drum rollers and a sweeper.
In terms of automation or new technologies assisting the work on the project, McMillan also said, "What we're starting to see in the industry is automated machine guidance. Typically, my staff has been trained using conventional surveying with stakes set every 50 feet. For this project, the contractor and our surveyors worked together to model the project. Then the contractor placed automated machine guidance on their grading equipment, and their grade checker ran around with a rover. They did a lot of this work without stakes.
"My team then coordinated with our survey crew to field check the grades with our models. So, we have two different models — the owner's and the contractor's — for quality control. This is the first project for my team whereby the concrete barrier is being placed by GPS. Cooper Engineering is using a slip form paver for this work and pre-modeled the profile and used GPS for horizontal control. We have stakes for our team to complete our inspection."
When funding is received, phase two will involve building a direct connector from westbound SR 56 to northbound I-5, replacing and enhancing the Del Mar Heights Road overcrossing, and constructing an additional westbound lane on SR56 to further improve area mobility. CEG
(All photos courtesy of Caltrans.)
