The 50-year-old Herbert C. Bonner Bridge, the sole highway link to Hatteras Island on North Carolina’s Outer Banks, faces several more years of withstanding salt air, tidal currents and coastal storms. But the September 16 federal court ruling in favor of the North Carolina Department of Transportation’s replacement strategy does appear to move the venerable, yet deteriorating structure a step closer to what state officials and local residents feel is a long-overdue retirement. 

U.S. District Judge Louise Flanagan refused to accept the Southern Environmental Law Center’s contention that NCDOT’s current plan to parallel the existing 2.7-mile long bridge across Oregon Inlet with a replacement structure doesn’t address long-term erosion problems along a narrow, unstable 11-mile section of Hatteras Islandone of the replacement project’s stated purposes and, therefore, a violation of the National Environmental Protection Act.

Incidences of damage from storm overwash have grown in both frequency and severity in recent years along State Route 12, including a new inlet created as Hurricane Irene moved across the Outer Banks in September 2011.

The lawsuit, filed on behalf of the National Wildlife Refuge Association and Defenders of Wildlife in July 2011, also argued that NCDOT and FHWA failed to fully consider a 17.5-mile “long bridge” alternative that would extend through Pamlico Sound to the village of Rodanthe, bypassing the island’s vulnerable, environmentally complex sections, but with a projected construction cost of $1.4 billion.

NCDOT countered that more than two decades’ worth of analysis and evaluation of alternatives justified its bridge replacement decision. In addition to a replacement structure, the agency plans to develop a long-term Route 12 maintenance plan based on a continued monitoring of Hatteras Island’s stability and environmental conditions.

Studies suggest that the barrier island is migrating inland at a rate of five to 22 feet per year.

Just weeks after the SELC filed its lawsuit, NCDOT accepted the $218.3 million bid for a replacement bridge submitted by the design-build team of PCL Civil Constructors and HDR Engineering. The project’s start has been delayed due to the SELC’s lawsuit and companion petition to the N.C. Department of Environment and Natural Resources asking that state-level environmental permits be denied.

The latter issue has yet to be resolved, nor has the SELC ruled out an appeal of Judge Flanagan’s ruling.

For now, NCDOT will focus on keeping the Bonner Bridge in shape this fall with $2 million of maintenance work, including patching the underside of the concrete deck and repairs to scour-damaged supplemental bridge supports. The agency estimates that more than $56 million has been invested to inspect, repair, and maintain the Bonner Bridge since the process of replacing it began more than two decades ago.

According to NCDOT, as many as 13,000 vehicles cross the Bonner Bridge during peak travel days in the summer, helping support the Outer Banks’ tourist-based economy that attracts more than two million visitors each year.