I-5 South County Improvements- Segment 2

The Project.

This 2.5 mile segment from Avenida Vista Hermosa interchange to Pacific Coast Highway was widened to provide a new HOV lane in each direction. The purpose of the project was to improve existing and future levels of service on I-5, while minimizing environmental and economic impacts.



  • Geotechnical Testing
  • Materials Testing

Project Fact:
This section of the I-5 currently sees up to 183,000 vehicles per day.

Leighton’s role as Quality Assurance testing was to provide soils and material testing services in accordance with California Test Methods and ASTM. Our Caltrans-certified technicians provided periodic field and materials testing for Engineer’s Acceptance to assist the roadway and structural inspectors. Our duties included quality assurance of the methods and frequencies for performing testing and inspection; random field testing of soils, aggregates, and Hot Mix Asphalt (HMA); and sampling and laboratory testing of construction materials, including HMA and structural Portland Cement Concrete (PCC). The laboratory testing was performed in Leighton’s Caltrans-certified lab to verify contractor compliance with Caltrans specifications.