Enhancing the I-5

By Luke Carothers

The Los Angeles County Metropolitan Transportation Authority’s (Metro) I-5 North County Enhancement Project (I-5 NCEP) is an ambitious undertaking that will ease congestion, improve safety, and accommodate booming growth along the 14-mile corridor between State Route 14 in Santa Clarita and Parker Road in Castaic.  The project broke ground in December of 2021, and is currently slated for completion in late Summer 2026.  The steps of this project include:

• Installing Intelligent Transportation System (ITS) improvements including count stations, closed-circuit television (CCTV), and ramp metering to nine on-ramps.
• Addition of one HOV lane in each direction along the I-5 between the SR14 and Parker Road interchange.
• Extending a northbound truck lane along I-5 from SR14 to Calgrove Boulevard, a southbound truck lane from Calgrove Boulevard to SR-14, and new/extended auxiliary lanes between
  interchanges at six locations.
• Reconstructing the Weldon Canyon overcrossing.
• Widening seven existing bridge structures between SR-14
  and Parker Road.
• Building retaining walls, sound walls, and a new concrete median barrier and guardrails.

Project management firm Hill International (Hill) has played a crucial role in supporting Metro constructing this ambitious project.  For Metro, the volume of traffic along the project corridor and its vital connection to the highway for residents and businesses in the North County necessitated a unique approach in order to manage the project successfully.  In this, Metro selected a construction services support team led by Hill International.  To help facilitate the project, Hill established a local field office for Metro that houses a team of roughly 50 consultants, Metro employees, and CalTrans oversight staff who work as an integrated project team.  

Hill team leader and Senior Construction Engineer, David Tiberi, notes the principal challenges that arise from this project’s important location. The 14-mile-long Project cuts through a hilly area and supports a heavy traffic volume, including truck traffic. Changes in elevation mean that the Project must contend with cuts and fills as well as a bridge replacement, seven bridge widenings, and 43 new retaining walls. Furthermore, in many areas, the spaces surrounding the construction zone are considered Environmentally Sensitive Areas (ESAs) and are off limits for construction access. This culmination of factors, according to Tiberi, has resulted in extremely tight working conditions. Accessing the work areas, especially the median, requires much of the work to take place at night, when traffic is reduced and therefore Caltrans allows lane closures.   Lane closures enable access for the slow-moving dump trucks and concrete trucks that need to merge from the work zone into traffic. Another feature of I-5 NCEP that further supports its description as ambitious is its installation of ITS improvements to enhance connectivity for the transmission of traffic data from the area to the Caltrans District 7 Traffic Management Center (TMC) in Los Angeles.

To achieve the project goals, Tiberi notes the importance of the multidisciplinary team, which is overseen by CalTrans.  This multidisciplinary team works out of the field office established by Hill in March of 2021, which has been crucial when contending with challenges to mobilization brought on by the Covid-19 pandemic.  This field office is fully operational 24-hours a day, 7-days a week, which helps align with the construction schedule, including substantial night shift work.  Technical experts in roadway and structure construction, environmental regulations, survey, project controls, risk management, and safety are all supporting the Project through the field office.  Another feature of Hill’s field office that has been effective at minimizing delays was the establishment of a CalTrans certified testing lab.  With no operating material testing lab specializing in highway construction within 40 miles of the project, Tiberi says that it was clear they needed their own lab to be able to test concrete, asphalt, and aggregates as well as perform batch plant inspection.  This lab allows the project team to provide material testing turn-around times needed to keep pace with the work.  The location of Hill’s field office, as well as the building of a testing lab, have allowed this multidisciplinary team to respond to the project’s unique challenges. 

With such an impact on the surrounding communities and businesses, Tiberi emphasizes the importance of keeping the public informed about upcoming construction work.  For I-5 NCEP, Metro has led the project’s outreach efforts.  These public outreach efforts are supported by Hill’s staff conducting community meetings, issuing construction alerts, and giving presentations to local elected officials at various public meetings.  Tiberi says that this ability to communicate information has allowed teams working on the project to communicate important safety and detour information that in many cases has minimized negative impacts and delays.  The I-5 NCEP is a major part of Metro’s long-term plans to make travel throughout the region safer, faster, easier, and more sustainable.  While the project is still years away from substantial completion in 2026, Tiberi says the project team is in a constant process of building upon lessons being learned, which is further supported by its collaborative, multidisciplinary nature.  As I-5 NCEP continues to be built, this ability to learn from challenges while adapting and overcoming will be crucial in maintaining the necessary pace of work.

LUKE CAROTHERS is the Editor of Civil + Structural Engineer Magazine. If you want us to cover your project or feature an article, he can be reached at lcarothers@zweiggroup.com.