Flatiron is the primary contractor for the project that began in February 2020. The work included:

• Upgrading a two-mile section of State Route 20 and straightening curves on a section of the highway.
• Widening segments of highway to create uniform 12-foot wide lanes and widening shoulders to a standard eight-foot width.
• Constructing a new bridge on the realigned section of the highway and increasing sight distances for motorists traveling on the highway.

To better understand the subsurface conditions, the project team did test-drilling of rock layers and then modeled the rock layers into an earthwork model. This allowed the team to fine-tune project schedules, maximize equipment spread efficiency and improve cost effectiveness. Besides rock modeling, drone technology and photogrammetry topographic surveys were utilized for data collection and analysis.

Approximately 280,000 cubic yards of rocks were removed, with about one-third of which requiring rock blasting. All of the material has been utilized on-site for the embankment construction.

The final work is providing enhanced safety and smoother rides on this major east-west route for local driver and commercial operators.

• The $34 million project was located a half-mile east of the Yuba River in eastern Yuba County, California.
• The new roadway meets current 55-mph highway design standards and provides improved sightlines around curves, improved stormwater drainage systems and updated safety barrier systems. 
• The project also included the construction of the Clear Creek Bridge, which is a 800-foot cast-in-place box girder bridge that was built on 60 feet tall falsework.