
With limited access, steep terrain, and a lack of foundation under its right-of-way, the 75-year-old side hill bridge on Southbound Interstate 5, north of Redding, was in need of replacement. Given its shape and the rocky terrain, the California Department of Transportation (Caltrans) came up with an innovative solution to address the problem. That solution was the $34.5 Shasta Viaduct. This new bridge spans over 800 feet, with a design that incorporates asymmetrical arches to account for the horizontal curve in the structure and the varying levels of elevation. Working through two of the largest devastating wildfires in the state’s history, the construction and design teams had their share of challenges. The result is a bridge that will withstand an earthquake, but also save taxpayers money by reducing maintenance costs. With its new service life is projected to last beyond 100 years, the greatest benefit of all is the increased safety to travelers.