Once complete, the Louisiana Highway 1 bridge will be one of the longest in Louisiana and the Americas. At approximately 17-miles long, the elevated structure will bring critical connection and enhanced resiliency to a key freight corridor that services 95% of energy production in the Gulf of Mexico.

The section currently under construction, Phase 2, will connect the communities of Golden Meadow and Leeville via an HNTB-designed, 8-mile elevated span. The bridge is replacing a long section of at-grade roadway that frequently requires closures and maintenance due to hurricane storm surge events. In addition to preliminary and final design, HNTB supports the Louisiana Department of Transportation and Development (LADOTD) with toll support services, pile driving analysis and construction engineering support services.

Planning a Resilient Design and Accelerated Schedule

With the goal to deliver a resilient structure that can extend beyond a conventional 75-year design life, HNTB coordinated with LADOTD and local stakeholders and contractors to develop a design and construction strategy for a bridge that can withstand the region’s most severe weather events, accommodate heavy freight and limit the disturbance of wetlands. The coordination and extensive research led to a bridge that was designed to accommodate hurricane force winds and storm surges, while utilizing top-down construction to limit impacts to the approximate 8-mile-long strip of wetlands it traverses. These efforts ultimately resulted in a set of plans that maximize constructability and environmental consideration while significantly reducing the project’s schedule and costs.


In addition to plans that accelerate schedules and reduce costs, HNTB also assisted LADOTD with securing $135 million in grant funding for the project, the largest award of the 2020 Infrastructure for Rebuilding America grant cycle.

Location: Louisiana

Client: Louisiana Department of Transportation and Development

Services: Preliminary and final design