Louisiana will seek private funding to replace the nearly 70-year-old, functionally obsolete I-10 Calcasieu River Bridge in Lake Charles.

Opened in 1952, the 6,605-ft-long through truss bridge carries 80,000 vehicles per day, double the volume recorded just 20 years earlier. In that time, National Bridge Inventory condition assessments for the bridge superstructure, substructure and deck have fallen to structurally deficient levels, with a sufficiency rating of 9.9 out of 100. During Hurricane Laura last August, an unmoored riverboat casino struck bridge piers, but caused no major damage.

With the estimated replacement cost ranging upwards of $800 million, the Louisiana legislature authorized the state's Dept. of Transportation and Development (DOTD) to solicit proposals for a design-build-finance contract that would also include corridor highway improvements to ensure the new bridge meets current design and safety standards. DOTD has already committed $85 million to the project, which also includes upgrades to two interchanges and a connecting local street segment, and will pursue federal funding to help offset the total replacement cost and potentially reduce user tolls.

DOTD plans to issue an environmental impact statement weighing three alternative replacement strategies sometime in 2021. Each alternative calls for reducing the existing main span vertical clearance of 135 ft by nearly half, to 73 ft, and minimizing risks from a 1994 spill of ethylene dichloride into the Calcasieu River, which supplies drinking water for Lake Charles and surrounding communities. That includes consideration of various foundation pile types and placement strategies, according to a DOTD fact sheet.

Under its current schedule, DOTD will make a decision on a preferred alignment in 2022, and award a contract early the following year.