Developing a Decision Model for Evaluating Transportation Alternatives in High-Hazard Coastal Areas

A Research Proposal

By: Courtney Colwell, Roxanna Farshchi, Thomas Jenkins, Junghwa Kim

Dr. Lynn Maguire, Adviser

Signature: _ _______________________________

Andy Coburn, Associate Director Program for the Study of Developed Shorelines, Client

Signature: __Andy Coburn______________________________

Masters project submitted in partial fulfillment of the

requirements for the Master of Environmental Management degree in

the Nicholas School of the Environment of

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Duke University

2013

Introduction

State Highway 12 runs for 130 miles along a strip of barrier islands off the North

Carolina coast known as the Outer Banks (map 1).  In many places, it is the only road

linking several towns to the rest of the Outer Banks and to the North Carolina mainland.

Along some stretches of roadway, the barrier islands are no more than about 357 yards

wide, putting the road at high risk of flooding from the nearby ocean (Smith, 2008).  

Map 1. NC-12 on the Outer Banks of North Carolina (Outer Banks Real Estate, 2010).

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North Carolina’s unique geographical position on the Atlantic coast makes the state

a target for hurricanes (Smith, 2008). Since 1851 North Carolina has experienced 46 direct

hits from hurricanes, 13 of which are categorized as major (Landsea, 2010). While there is

still uncertainty about an increasing number of storms with climate change, the intensity of

hurricanes in the Atlantic is likely to increase (Pilkey, 2011). Given these factors, the Outer

Banks is not conducive to having a long-term static road structure and will likely

experience more issues related to such structures as time progresses.

Within the past decade, two hurricanes have breached the barrier islands and

destroyed the road, making parts of the Outer Banks accessible only by boat (Fig. 1). In

each instance, the breaches have either been refilled with sand or spanned with a bridge to

maintain the Highway 12 corridor (Morris, 2011). 

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Figure 1. Aerial photo of breaches in NC-12 after Hurricane Irene (NOAA, 2011).

The Herbert C. Bonner Bridge, which carries Highway 12, is an area of particular

concern.  Completed in 1963, the bridge spans Oregon Inlet and connects northern

Hatteras Island (Pea Island National Wildlife Refuge) to Bodie Island (map 2), which then

connects to the mainland via NC-64 across the Roanoke and Croatan Sounds.  Because

Bonner Bridge exists in a dynamic environment subject to constant wave action and

shifting sands, it has experienced rapid deterioration since its installation (Dean, 2012).  

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Map 2. Map of Bonner Bridge and Oregon Inlet (Southern Environmental Law Center (1), 2011).

Recently, environmental regulators in North Carolina signed off on a replacement plan

proposed by the North Carolina Department of Transportation (NCDOT) to replace Bonner

Bridge in the general area it currently occupies. Many environmental groups, such as the

Southern Environmental Law Center, oppose this plan and would prefer to see the long

bridge alternative, which would circumvent the Pea Island National Wildlife Refuge. The

replacement will cost roughly $200+ million, but still requires several permits before

building can begin (Associated Press, 2012). Since the 1980s, nearly $100 million has been

spent maintaining and rebuilding sections of NC-12. Hurricane Irene in 2011 caused at

least $10 million in damage and rebuilding does not present itself as a sustainable long-

term plan (NCDOT, 2012). The rebuilding process is also complicated because of the many

stakeholders involved including, but not limited to, the following: NCDOT, National Park

Service (NPS), U.S. Fish and Wildlife Service (USFWS), and local governments such as Dare

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and Hyde Counties. With many stakeholders come different interests to protect, which

further confounds the decision making process.

To better maintain public access south of Oregon Inlet the Program for the Study of

Developed Shorelines (PSDS) would like to develop a decision making framework to

evaluate current and alternative methods for transportation in this area. PSDS, located at

Western Carolina University, “examines the scientific basis for managing developed

shorelines in a time of rising sea level and advocates for the development and

implementation of responsible strategies, plans, policies and actions that promote the long-

term sustainability of our nation’s coastal ecosystems” (PSDS, 2012). The decision making

framework will assess multiple attributes of each alternative including economic,

environmental, and social feasibility.

Problem

The problem to be addressed is how best to provide, manage, and maintain a viable

and reliable transportation corridor between Oregon Inlet and Rodanthe along the North

Carolina coast (map 2) over the next 50 years. As described above, the current method is

not ideal in this dynamic coastal environment, and a number of stakeholders are not

content with the status quo. The project will provide a decision analysis framework to

identify, evaluate, and compare strategies.

 Objective

The objective of this project is to construct a decision analysis framework that

elicits, evaluates, and incorporates disparate stakeholder preferences along with objective

data to demonstrate the utility of various management strategies for providing continued

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public access from Oregon Inlet to Rodanthe and areas south for the next 50 years. The

framework will allow decision makers, at the local and state level, to evaluate and identify

the alternative that best satisfies a number of critical criteria for providing continued

public access between Oregon Inlet and Rodanthe. This is particularly important for long

term management and when considering climate change adaptations. In addition to

eliciting stakeholder preferences and building a decision analysis framework, a study will

be conducted to identify the financial feasibility of implementation of each alternative. The

majority of this information will be collected through literature review and supplemented

by informational interviews with stakeholders.

To complement the decision framework and literature review, a policy analysis will

be conducted to formalize the social and political aspects of management of public

highways in dynamic coastal areas. The analysis will focus on defining the policy issue,

describing the legal mandates involved, identifying the human ecology of the relevant

policy processes, and analyzing the policy alternatives within the decision analysis

framework. Together these products will provide a comprehensive assessment of the

current management regime and possible alternative management approaches, while

integrating stakeholder preferences. This approach will allow future decision makers to

fully understand the social and political context of the issue and the tradeoffs associated

with each management alternative.

Background

Our problem and objective are highly interdisciplinary in nature, and thus a

background understanding of barrier island morphology, Outer Banks transportation

history, coastal transportation engineering, and multi attribute decision-making is

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necessary. A survey of papers in these fields that relate to our project emphasize the need

for a clearer understanding of how decisions are made in the management of

transportation in our study area.

Barrier Island Dynamics

Facing the challenges of storms, waves, sea level rise, and erosion, coastal

communities around the world must innovate with new methods to provide transportation

and development in ways that minimize conflict with environmental threats and

ecologically sensitive areas (Davenport & Davenport, 2006). Highway 12 exists on a highly

dynamic barrier island that has been engineered for stability. In the 1930’s, the Civilian

Conservation Corps used bulldozers to build tall dunes along the Outer Banks as part of the

New Deal work programs. These dunes lack the ecological features of natural dunes

(Coastal Care, 2012). Magliocca et al. (2011) use simulation modeling to show the future

evolution of an artificially engineered barrier island similar to the Outer Banks. In fact,

many of the input parameters to the model come from the Outer Banks barrier island

network. They conclude that building artificially high dunes in order to protect inland

development actually places that development at higher risk of flooding. The engineered

dunes prohibit natural replenishment and migration of the island, putting it at further risk

from sea level rise and storm-induced overwash events.

Highway 12 History

The section of Highway 12 that is our focus area was constructed in 1952 through

Cape Hatteras National Seashore and Pea Island National Wildlife Refuge. Bonner Bridge

across Oregon Inlet was constructed in 1963 to facilitate access to eight villages south of

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Oregon Inlet. This construction required dredging to stabilize the inlet channel. The

dredged sand dumped offshore into deep water resulted in loss of sand supply to the

southern edge of the inlet, and increased erosion rates on the northern end of Pea Island

(Riggs et al., 2008).

In 1989, a rock jetty was built to protect where Bonner Bridge comes ashore at the

south end of Oregon Inlet. The dynamic north end of the inlet and the stabilized south end

of the inlet have often resulted in rapid changes in the inlet bathymetry in the past 20

years. The shoaling that is a direct result of the inlet stabilization has come close to

interrupting boat traffic in and out of Pamlico Sound. Also, the constant inlet shoaling and

erosion has taken a toll on the bridge pilings, many of which have required additional

support in recent years. This jetty interrupted sand delivery to the north end of Pea Island,

requiring about 7.7 million cubic yards of sand delivered between 1989-2005. Despite the

nourishment, the north end of Pea Island continues to experience once of the fastest

shoreline erosion rates across North Carolina. (Riggs et al., 2008). Thus, Highway 12 has

been relocated westward in four locations where it is now adjacent to the Pamlico Sound

shoreline (Riggs et al., 2008).

Managing Highway Breaches

In 1974 North Carolina passed the Coastal Area Management Act (CAMA) to

preserve the natural beauty of the coast, while allowing for development (CAMA, 1984). To

make policy decisions CAMA provides for the creation of a panel known as the Coastal

Resources Commission (CRC), involving stakeholders from multiple sectors (CAMA, 1984).

If there is a breach in the highway an emergency meeting of the CRC is held to set

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temporary rules and guidelines (NCDCM, 2010). During this time the CRC decides what

information must be collected before rebuilding a road including considerations for the

Dredge and Fill law. If it is determined that the existence of a new or migrated inlet

represents an extraordinary situation in which life or public safety is in imminent danger,

the Secretary may authorize DCM to issue special emergency permits that suspend the

normal processing and public notice requirements normally associated with such a permit

(NCGS 113A-119, 113-229), thereby significantly expediting permit issuance (NCDENR,

2004). This has become the norm; therefore, little, if any, thought is given to what else can

be done in these situations (NCDENR, 1974). Additionally, emergency CAMA permits must

be obtained at this time by the NCDOT (NCDENR, 1974). Emergency CAMA permits provide

the Coastal Resources Commission an avenue for post-disaster decision-making. They can

decide to whom and for what to grant a permit. These rules are integral to having flexibility

in the face of disaster.

The traditional solution to environmental threats has been to preserve Highway 12

in its current location through rebuilding, while alternatives such as relocating the more

vulnerable parts of the highway to a bridge and abandoning nourishment and dune

protection in the Pea Island NWR have been dismissed (FHA & NCDOT, 2010). The

decision making process in this unique area has the ability to affect a diverse group of

interested parties, and the ecosystem at large. Island residents and the tourism industry

depend upon safe and reliable transportation. The environment and the industries it

supports can be significantly impacted by decisions that support the transportation

network. Much is at stake here, and to account for it all when making future decisions

requires a comprehensive approach.

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Multi-criteria tool

Coastal managers in Europe have demonstrated the effectiveness of a multi-criteria

analysis methodology to manage socially diverse and ecologically fragile coastal

ecosystems. This analysis identifies the different actors and stakeholders who affect and

are affected by management decisions. It seeks to elicit their values and preferences of

different management choices according to criteria developed by the researcher. The

researchers then develop a multi criteria tool to demonstrate the rating of these choices

compared with one another on a familiar scale.

On France’s Mediterranean coast, eroding shorelines threaten coastal development

in a lagoon and barrier island ecosystem. The area has traditionally been managed through

narrowly focused, engineering-based solutions that include shoreline hardening similar to

the Oregon Inlet jetty. Roca et al. (2008) applied a multi-criteria analysis to choose a new

methodology for accommodating the changing coastal ecosystem in Lido de Sete, France.

Wide stakeholder involvement was paramount to ensuring a balanced and informed

evaluation of shoreline management alternatives. The respondents tended to choose

adaptive shoreline management strategies that accommodated the region’s natural

morphology over the traditionally used hard engineering strategies that tried to fight

physical processes. The key learning point here was that having input from a broad range

of interested parties resulting in a less environmentally damaging outcome that addressed

the varying needs of the parties (Roca et al. 2008).

Similarly, a multicriteria analysis was used to identify new ways to manage an

estuarine system in northern Spain. Dredging done by a local shipyard was interrupting

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sediment supply in the estuary, leading to conflicts between recreational users of the

estuary, industry, agriculture, and the health of the ecosystem overall. The analysis was

useful to break the traditional top-down approach of management decisions and to map

compromise solutions between parties that led to better social and environmental

outcomes (Garmendia et al, 2010).

A long-term consequence of the reactionary emergency response policies in North

Carolina might be that NCDOT and other stakeholders involved in the management of

Highway 12 may not consider other potential transportation methods. We believe we can

add to the history of success stories in coastal management by applying a multi criteria

analysis to the transportation problem of North Carolina Highway 12.

Methods

Multi Attribute Utility Theory (MAUT) is a method by which consultants may aid

decision-makers in determining and ranking their weighted values regarding the

alternatives and tradeoffs they face in a particular decision. In MAUT, individual

alternatives have an individual value known as their “utility,” and then are compared

against each other for their “weighted value” (Maguire, 2012). For example, there are three

cars available in a certain dealer. Each has a different utility to Joe, who is seeking a car

based on speed and price, which can be seen in table 1 below. MAUT allows Joe to compare

these individual utilities cross referenced with their natural ranked order (as a result of

which had the highest utility to lowest utility) and thus calculate the weighted value of each

alternative. Once the weighted values are obtained, the scale of “best” through “worst”

outcomes can be seen, and a car may be chosen.

Table 1. MAUT Chart.

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Vehicle 1 Vehicle 2 Vehicle 3Utility of Speed or USpeed

0 .5 1

Utility of Price or Uprice

1 .5 0

In our situation, we plan to develop a decision analysis framework based on a series

of questions asked of key stakeholders to determine what they want and require in terms

of access within the study area. Our questions will be based upon baseline necessities for a

general route to provide access to the Outer Banks south of Oregon Inlet – whether this

route can maintain ecological integrity, is financially feasible, is reliable, and can

accommodate rapid storm evacuation.  Through this series of questions we will determine

what priorities exist, what criteria are most valued by stakeholders including NCDOT, NPS,

USFWS, and local governments and what tradeoffs are often made in the Outer Banks

transportation decision-making process. This will result in a multi-attribute decision tool

that will be used to evaluate the following transportation alternatives proposed by PSDS:

1) status quo (continuing reactive management), 2) floating bridge, 3) system of bridges

(long bridge from Oregon Inlet to Rodanthe), 4) high speed ferry system. Ultimately, the

decision analysis framework will illuminate the tradeoffs associated with each alternative

using the input from decision makers and stakeholders.

Aside from the general Nicholas School timeline for Masters Projects, our group

members will follow the project-specific time table below to take steps towards completing

the study.

Table 2. Group time table.Task Individual Due

Collect information for literature review Everyone Beginning of ClassesSubmit proposal for final approval Everyone 28 September 2012Submit IRB proposal for approval Roxanna 5 October 2012

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Identify stakeholders for interview Courtney 8-14 October 2012Work on individual focus areas* Everyone 8-28 October 2012Conduct interviews Everyone Late October - DecemberContinue working on individual focus areas* Everyone Late October - DecemberInput data into NVivo Roxanna As interviews are conductedSynthesize information and develop framework Everyone January – early FebruaryComplete first draft Everyone February 25(*) To best focus our attention, we decided to divide the project into focus areas. Specifically, Courtney will focus on the policy analysis, Thomas and Junghwa on the literature review and gathering factual information about the alternatives, and Roxanna on managing the interview information. In addition, all team members will participate in conducting interviews and developing the decision tool when all interviews have been completed. All team members are responsible for editing products, supporting the team as a whole, and conducting additional research as needed.

Interview Process

When conducting interviews, two categories of questions will be administered.

There will be both opinion- and fact-based questions. While the opinion questions are

intended to help elicit the preferences within the decision analysis framework, the fact-

based questions will look to supplement the literature review in both constructing the

skeleton of the framework itself (through developing the questions) as well as the looking

at the feasibility of alternatives in the final analysis. Prior to administering the opinion-

based questions, approval from the Institutional Review Board must be received regarding

the ethics of the questions, ensuring that these questions will not cause harm to those

interviewed.

Questions will be initially asked of a variety of stakeholders, including NCDOT,

National Park Service, US Fish and Wildlife Service, and local government officials,

recommended by PSDS, with differing views on the subject area. They in turn will be asked

to give additional expert contacts with opinions differing from their own in the area. This

“snowball effect” will allow the team to obtain a wide sample of opinions and interviews. If

there are enough interviews and information to evaluate, the software tool NVivo will be

used to organize and evaluate both the factual and opinion based information. Roxanna will

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be the only team member working on NVivo to organize and evaluate the interviews

conducted in order to maintain uniformity for software analysis reasons. In the case that

there are not enough interviews to effectively utilize NVivo Software, Microsoft Word will

be used to organize and evaluate the interviews.

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Format of Report

We expect that our decision making framework, delivered in the form of a written

report, will be used primarily by coastal managers when faced with complex decisions

regarding development in coastal areas.  This framework will be comprehensible to

managers, scientists, government agencies and other coastal stakeholders so that it may be

used by a variety of parties. By making this framework clear and understandable we hope

to facilitate conversation between these various participants. We hope to foster a decision

making process that compares concise alternatives that can be evaluated based on uniform

aspects. We also hope that the framework we develop can be applied for similar coastal

problems in other areas.

Outline

A. Introduction

a. Problem Description

b. Project Goals

B. Materials and Method

a. Literature Review

b. Interview Process

c. Description of Multi-Attribute Utility tool

C. Results

a. Factual implications of alternatives

b. Stakeholders’ preferences of alternatives

c. Development of Decision Theory Tool

D. Discussion & Conclusion

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Source and Amount of Support

We will require access to computers and software to run our multiple attribute

analysis which we will obtain at the Nicholas School and the Duke University Marine Lab.

To enable communication amongst the group members and our client we will use a

combination of telephones, Skype and the teleconference room located in the Nicholas

School.  Any additional support we may require will be discussed in advance with both our

adviser and client.

Faculty

Our faculty adviser is Dr. Lynn Maguire who will provide guidance and support

throughout the duration of the project. Our client is Andy Coburn, the Associate Director of

the Program for the Study of Developed Shorelines at Western Carolina University.

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