A joint venture made up of Flatiron Construction Corp., Skanska, and Stacy and Witbeck (FSSW), was recently awarded an additional segment on the North Coast Corridor project in San Diego County.

The $224-million contract awarded to FSSW includes construction of eight miles of new HOV/carpool lanes on Interstate 5 (I-5) – one in each direction – between Manchester Avenue in the City of Encinitas and Palomar Airport Road in the City of Carlsbad. In addition, work will include several new auxiliary lanes, ten new sound walls on private property, several culvert rehabilitations, and the installation of ITS equipment (CCTV cameras, fixed changeable message signs, and fiber optic lines). Work is underway and is slated to complete in August 2021.

The project is a part of the larger $1.1 billion-Build NCC project. Build NCC is the first phase of construction on the North Coast Corridor (NCC) Program in the north San Diego County coastal cities of Solana Beach, Encinitas, and Carlsbad. The North Coast Corridor Program is a 40-year, $6 billion vision to build transportation, environmental, and coastal access projects to I-5, its bridges, adjacent railways, and lagoons.

For this latest segment, the FSSW team, working with Caltrans and the San Diego Association of Governments (SANDAG), are phasing the work into two distinct stages. First, crews are placing k-rail along the inside shoulder in both directions for the full eight miles, allowing for a safe work zone to widen the inside of the highway, says Caltrans Public Information Officer Edward Cartagena.

Once the 18-month-long job of reconstructing the inside of the highway is complete, crews will shift the k-rail to the outside shoulder to widen the outside of the highway. The majority of work will be completed at night or behind k-rail, to limit the impact to the daily commuting public, says Cartagena.

Additionally, during the last 18 months of outside widening work, a series of extended ramp closures are planned to allow crews to reconstruct and tie-in the on- and off-ramps over the course of a full weekend.

Besides this latest segment awarded, the FSSW joint venture is working on several other active Build NCC projects. This additional work includes:

• The $257-million San Elijo Lagoon Highway Bridge & Community Enhancements. This project widens San Elijo Lagoon Highway Bridge to accommodate new I-5 HOV/carpool lanes, and lengthens the bridge to improve lagoon tidal flow in the lagoon below. It also improves bike and pedestrian paths.
• The 70-million San Elijo Lagoon Double Track & Chesterfield Crossing Improvements: This includes an additional 1.5 miles of second main track in the community of Cardiff-by-the-Sea, replacement of the more than 80-year-old wooden trestle San Elijo Lagoon rail bridge with a modern, double-track, concrete bridge, and improved signal and safety at the Chesterfield Drive at-grade crossing.
• The $117.3-million San Elijo Lagoon Restoration, which includes restoring the more than 900-acre San Elijo Lagoon, improving tidal circulation, preserving the north San Diego County coastline, and enhancing lands and waters for native plants and animals.
• The $6.8-million Coastal Rail Trail Bikeway, which will construct a 1.3-mile, separated biking and walking path to link the community of Cardiff-by-the-Sea with downtown Encinitas.

Mario Martinez, Flatiron project manager, says the San Elijo Lagoon Highway Bridge & Community Enhancements project is “incredibly complex” and requires careful coordination between FSSW, drilling sub-constructor Condon-Johnson & Associates, Inc., and Caltrans. He says the project, which is about 53 percent complete, consists of 17 bridge columns that are 10 ft in diameter and nearly 300 ft deep in the San Elijo Lagoon basin.