NO. 4 ROAD: Widening Orange County

Dec. 7, 2022
Segment 2 of the I-5 Oso Parkway to Alicia Parkway gives California motorists more room

The Interstate 5 Oso Parkway Project (Segment 2) spans approximately 3-miles of I-5 through the southern California cities of Mission Viejo and Laguna Hills. 

Flatiron West, Inc. widened this stretch of highway in Orange County, one of the most populated counties in the United States. The project gives motorists an additional general-purpose lane in each direction, while also improving on- and off-ramps to help with current and future travel demands.

This multi-segment project, expected to be finished in mid-2024, will feature seven bridges in three locations (La Paz, Oso Parkway, and El Toro Railroad), and a full interchange reconstruction at La Paz Road. Construction of 22 retaining walls of multiple types and mechanically stabilized earth (MSE) systems are required for the complexity of this project.

Flatiron must manage large-scale paving operations as a part of the improvements to the interstate, while also providing significant improvements to drainage and electrical infrastructure installations that  involve over 100 drainage systems and over 3 miles of electrical infrastructure installations. Segments of this work is on, over, and adjacent to active freight and commuter rail lines and over ancillary waterways, which require the management of environmental permitting.

In addition to providing Caltrans with engineering solutions to accommodate the construction of the new structures, Flatiron is also maintaining traffic in both directions with minimal interruptions to commuters.

The project faced many challenges, but with the use of Collaborative Partnering, project delays were avoided. The team utilized the partnering relationships established during the initial phase of construction to elevate issues through the established escalation ladder. This kept the project moving forward in resolving all environmental, outside agency, stakeholder, schedule, and cost issues.

The project team also faced issues relating to cost and scheduling on the Temporary Northbound La Paz Off-Ramp. The team took time upfront to discuss the process expectations and decide how to monitor progress. Through their communications, and establishing clear expectations, the development of a temporary off-ramp relieved the schedule of critical railroad work windows, which allowed the resolution of major issues to take place concurrently.

This project team did outreach events, such as the Mental Health Awareness Stand Down. Flatiron, along with the Associated General contractors (AGC) of California, Caltrans, the Orange County Transportation Authority (OCTA), and the Southern California District council of Laborers, placed mental illness in the spotlight, teaching the workers the signs of mental health issues and substance abuse issues.

 Project Manager Michael Armienti commented on the safety precautions put in place on the I-5 Oso Project.

“Safety is our highest priority on every project. Keeping our clients, employees, subcontractors and the public safe is our primary focus above everything else. Using our 31 years completing complex roadway, structure and bridge construction we have developed a safety approach focused on identifying safety hazards, mitigating them through engineered solutions, and implementing a compliance and behavior based site specific safety program on-site. At the beginning of each day, crews gather for our daily planning meeting where they review upcoming work for the day, including key safety concerns for operations, and perform the days stretch and flex to lessen potential injuries as the project team begins work. These daily meetings are supplemented by weekly Safety Toolbox trainings selected based on relevant, timely activities happening that week.”

The project is well underway, and the team is making great progress. The team expects the project to be done in mid-2024. R&B

Project: I-5 Oso Parkway to Alicia Parkway (Segment 2)

Location: Mission Viejo and Laguna Hills, California

Owners: Orange County Transportation Authority (OCTA)/California Department of Transportation (Caltrans)

Designer: Transystems Corporation

Contractor: Flatiron West, Inc.

Cost: $130 million

Length: 2.7 miles

Completion Date: May 2024

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