Evaluating Transportation Alternatives for Hattras Island, North Carolina Outer Banks
Abstract
The North Carolina coast includes a dynamic chain of barrier islands known as the
Outer Banks. Transportation management on these islands has been the subject of debate
over the past two decades because of the high cost of maintaining highway NC 12. The
road is subject to frequent sand overwash and storm damage that causes interruptions
in services and access and the bridge over a major inlet needs replacement. Interest
groups disagree about the best solution, with some most concerned about environmental
damage, some about economic impacts of service disruption, and some about emergency
evacuation. We interviewed nine stakeholders from federal, state, and local government,
citizen action groups, and environmental non-governmental organizations, asking them
questions about their preferences pertaining to transportation in general and specific
alternative transportation methods for the Outer Banks. The alternatives we researched
were: (1) replacing the imperiled bridge with a new bridge across the same inlet (Short
Bridge Plus), which would not alleviate the road maintenance difficulties on the islands;
(2) building a long bridge through the sound behind the chain of barrier islands bypassing
the troublesome road sections (Long Bridge) at very high initial cost; and (3) using
ferries to provide transportation to the barrier islands (Ferry System), requiring
extensive dredging of coastal habitat and high operational costs. Using data from
archived reports and from our interviews, we compared these alternatives in terms
of (1) access disruption from storm impacts (in days), (2) short-term cost (dollars),
(3) long-term cost (dollars), and (4) environmental impacts (acres of habitat disturbed).
We then interviewed three key stakeholders from state government, an environmental
organization, and local government to determine how important each of the four factors
was to each respondent in choosing a transportation alternative. By combining our
evaluations of each alternative with the stakeholders’ judgments of importance, we
found that the state representative chose the Short Bridge Plus, the environmental
organization representative chose the Long Bridge, and the local government representative
chose the Ferry System. Because some of these calculated results contradicted what
these three respondents told us they preferred, we examined the sensitivity of our
calculated results to changes in short and long-term cost estimates, acres disturbed
and relative importance of the four factors. A consistent result of our sensitivity
analyses was that stakeholders would often switch their preferred alternative to the
Long Bridge. Therefore, we believe the Long Bridge might be a point of compromise;
however, the massive funding required to build this alternative diminishes the likelihood
it will be implemented.
Type
Master's projectPermalink
https://hdl.handle.net/10161/6870Citation
Kim, Junghwa; Colwell, Courtney; Jenkins, Thomas; & Farshchi, Roxanna (2013). Evaluating Transportation Alternatives for Hattras Island, North Carolina Outer Banks.
Master's project, Duke University. Retrieved from https://hdl.handle.net/10161/6870.Collections
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