The Herbert C. Bonner Bridge is a lifeline along the Outer Banks, and the N.C. Department of Transportation wants to replace it with a new bridge over Oregon Inlet. NCDOT issued a press release reviewing the bridge's history and explaining the repairs needed to keep the bridge safe.
According to DOT, as many as 13,000 vehicles cross the bridge during peak travel days in the summer, an important part of North Carolina's $19.4 billion per year tourism industry. With landmarks like the Cape Hatteras Lighthouse, one quarter of the county's overall economic impact comes from Hatteras Island tourism alone.
The crucial lifeline is in trouble, DOT reports. After 50 years of weathering many storms, enduring harsh current and sustaining numerous boat crashes, engineers say the bridge needs to be replaced. The replacement project is on hold because of lawsuits, so DOT is pressing forward with costly repair work to keep the barrier island connected.
The department has already spent nearly $56 million on repairs, maintenance and special inspections since 1990 to fortify the bridge. Another $2 million in repair work is scheduled to begin this fall. "We simply can't sustain this model much longer," said NCDOT Chief Deputy Secretary of Operations Jim Trogdon. "The longer we wait, the more taxpayer money is spent patching a bridge that must be replaced, and the risk becomes greater that we could have to close the Bonner Bridge before the new one is ready."
DOT built the $4.1 million bridge in 1963 to extend Highway 12 over Oregon Inlet. At that time, the existing ferry route could no longer keep up with the growing traffic.
The harsh salt air has taken a toll on the bridge's steel and concrete, and the turbulent waters of Oregon Inlet are constantly shifting the sand on the ocean floor, which causes problems around the piers that support the bridge.
"The concrete is essentially rotting from the inside out as salt has found its way to the internal reinforcing steel, causing the steel to corrode," said State Bridge Management Engineer Greg Perfetti. "We've also had problems with what's called scour over the years, where the sand around the piers in the ocean floor gets washed away. The sand is critical to keeping the piers steady, so we've had to take many steps to protect and secure the piers."
Perfetti emphasized that the bridge is safe for drivers right now because of the extensive repair work and says DOT would close it immediately if safety becomes a concern.
In July 2011, the department awarded a $215.8 million contract for design and construction of a new bridge. Design work began immediately and construction of the new bridge was set to begin in early 2013. However, a lawsuit filed in September 2011 by the Southern Environmental Law Center has put the project on hold.
"This project has been studied more than any other project in the state's history," said Trogdon. "We held extensive public outreach and addressed concerns and comments from state and federal environmental agencies, and took all of this into account in making our decision. Anytime we plan a transportation project, we have a responsibility to meet the needs of that community while also doing the least harm to the environment."
For now, DOT will continue doing all it can to keep the bridge safe and the lifeline open.