The project encompassed the construction of a separate freeway bypass system from the junction of Interstate 5 and Interstate 805 to the Del Mar Heights Road Interchange and also included construction of a diamond-type interchange at Carmel Mountain Road, and adding auxiliary lanes to the existing mainline lanes, including shoulder widenings.

Many project goals have been established to reduce traffic congestion and improve safety along this corridor. In whole, four new lanes have been added in each direction. This project included construction of safer bridge foundations to withstand earthquakes, and the separation of merging truck traffic from the interchange and is intended to reduce the merging and weaving of traffic by improving access to SR-56 and the local roadways.

The most challenging component involved maintaining the daily traffic volume within the corridor. The project team dealt with traffic volumes of 261,000 vehicles per day. Traffic projections for the year 2015 indicate volumes will be close to doubling today’s figure.

Slated as a large structure job, the contract elements included construction of 12 bridges ranging from existing structure widenings to the completion of the largest viaduct, which consisted of six separate frames totaling 1,018 meters in length. Major components of substructure work included: a Plantable Geosynthetic Reinforced Wall (PGR wall), which required detailed scheduling and planning to place 21,300 cubic meters of soil cement foundation, 24,100 meters of stone columns to create the PGR wall; 4,400 meters of CIDHP; 29,000 cubic meters of structure concrete (bridge); 14,750 cubic meters structure concrete (retaining wall); as well as the usual clearing and grubbing; grading; PCC pavement and drainage work.