Chapter 1 Purpose of, and Need for, Action 1.0 Purpose of, and Need for, Action

The Department of Transportation’s (NCDOT, 2005) 2006 to 2012 Transportation Improvement Program (TIP) includes the replacement of the Herbert C. Bonner Bridge (Bridge No. 11) over in Dare County (TIP Project No. B-2500). Consequently, studies are underway in accordance with the requirements set forth in the National Environmental Policy Act (NEPA) of 1969, as amended. This purpose and need statement explains why an improvement should be implemented. The project location is illustrated in Figure 1-1.

1.1 Project Need

The need for a crossing of the Oregon Inlet will continue past the end of the service life of Bonner Bridge. A NCDOT Bridge Inspection Report from July 2004 rates the present condition of the bridge as “poor,” with a sufficiency rating of six out of 100. The bridge is classified as structurally deficient. This report also estimates the remaining practical service life of the Bonner Bridge to be two years (2006), indicating a need for ongoing maintenance and rehabilitation. The Bridge Inspection Report indicates there are places on the bridge where there is deterioration of bridge girders and substructure. Three needs relate to the replacement of the Bonner Bridge:

1. Continued demand for convenient daily and emergency access across Oregon Inlet is expected.

2. The natural channel or gorge through Oregon Inlet migrates. A replacement bridge needs to provide spans of sufficient height and width for navigation through the anticipated area of future natural channel migration, helping to reduce future dredging needs, dredging impacts, and the cost of dredging.

3. The southern terminus of Bonner Bridge is north of portions of NC 12 threatened by shoreline erosion and overwash. Placing the southern terminus of a replacement bridge or a long-term NC 12 maintenance and protection project south of these areas will reduce the frequency of maintenance of these threatened segments of NC 12.

The following paragraphs describe these needs.

1.1.1 Need for Access across Oregon Inlet The existing crossing provides the only highway access to . The only other way to access the island is via the Ocracoke Island to Hatteras Island ferry. The need for continued access to Hatteras Island with a capacity equivalent to that provided by the Bonner Bridge is reflected in the following ways:

• Tourist use of Hatteras Island (including the use of National Seashore) use of the National Wildlife Refuge, and Dare County’s reliance on tourism as its primary industry.

Bonner Bridge Replacement SDEIS 1-1 NCDOT TIP Project Number B-2500

Cap

Broad Creek e Hatteras NationalTo Na ATLANTIC OCEAN 345 12

g s Head WANCHESE Bodie

Island Sea

s hore

Roanoke N Island

Duck Island Terminal Groin Canal Zone Hot Spot Bonner Cape Hatteras National Bridge

Oregon Inlet

PROJECT LOCATION

S eashore 12

Sandbag Area 0 1 2 KM Pea Island Hot Spot 0 1 2 Miles National Wildlife Refuge

17 CURRITUCK 186 32 615 ATLANT 258 13 37 CAMD 168 GATES 158 E 137 N NORTHAMPTON 158 34 158 12 OCEAN 11 37 PASQUO17 343 35 158 305 45 PERQUI 561 T HERTFORD A 343 561 CHOWAN NK 305 37 M 17 I AN C 158 42 S Elizabeth Duck 258 34 308 13 32 City Southern 305 Shores BERTIE 903 Edenton Kitty Hawk 42 45 37 ound 308 32 rle S Kill Devel 11 ma 12 Hills 17 Albe 125 32 Nags Head PROJECT 17 308 264 64 Whalebone 44 13 308 VICINITY 111 142 64 64 125 345 42 Williamston 94 t 12 64 WASHINGTON Roanoke 64 Island Inle TYRRELL DARE n go 12 MARTIN 264 re 171 45 O 13 17 99 903 30 32 Hatteras 99 45 Rodanthe Rodanthe 'S' 264 BEAUFORT Island Washington 94 Curves Hot Spot 33 HYDE Waves 264 Lake 12 43 Mattamuskett Salvo PITT 99 264 102 92 P Hatteras amli co R Chicamacomico 33 iver d Avon Island RODANTHE 118 306 n Sou Buxton Life Saving Station 33 CRAVEN Hatteras Emergency 55 43 Pamlico Frisco Ferry Dock 304 New Bern 306 17 12 70 55 Ocracoke 41 PAMLICO Island Cedar 55 306 Island 58 Neu s NCDOT Projects e Ri JONES ver 12 17 70 TIP Project No. R-3116 306 TIP Project No. R-4070D Havelock CARTERET ONSLOW 101 70 TIP Project No. S-4004 58 TIP Project No. R-3116A 24 TIP Project No. R-3116B 24 58 Morehead City TIP Project No. R-3116D TIP Project No. E-4729 172 North PROJECT 0 10 20 KM TIP Project No. R-3116E 210 TIP Project No. R-3116F N AREA 0 10 20 Miles Carolina

Figure PROJECT LOCATION MAP 1-1 Tourism is the number-one industry in Dare County and on Hatteras Island. The tourist industry creates a large number of local jobs and generates substantial revenue for Dare County and the State of North Carolina. Sixty-one percent of the employment in Dare County relates to the tourism industry. Dare County promotes tourism during the peak (summer) season and the development of “shoulder” season tourism (in the spring and fall). The labor force in Dare County increases by approximately 75 percent from off-peak season to peak season. In 1999, the seasonal economic revenues represented more than 70 percent of the annual economy in Dare County ( Chamber of Commerce, 2003). Abundant natural resources will continue to be a major draw for tourists.

Statistics provided by the National Park Service (NPS) (see Table 3-6 in Chapter 3) indicate that total visits to the Cape Hatteras National Seashore in 2002 were nearly 3.1 million, a 40 percent increase over the 2.2 million visitors reported in 1990. For the three-month period of June through August 2002, total visits numbered nearly 1.48 million. The Cape Hatteras National Seashore is home to many species of flora and fauna and a number of biotic communities. It is a popular local, state, and national vacation destination. Visitors enjoy a variety of activities, including birding, fishing, surfing, windboarding, swimming, hiking, and attending interpretive programs offered by NPS rangers. The Pea Island National Wildlife Refuge reports 2.75 million visitors annually, including birders, canoeists, beach users, fishermen, and photographers (Pea Island National Wildlife Refuge web site, October 2, 2003). Eco-tourism, a concept of combining ecological awareness and tourism, has become a new marketing tool for all of northeastern North Carolina. Dare County supports the concept of combining natural resources and tourism to promote the area’s ecological values (2003 Dare County Land Use Plan).

• Reliance of the permanent Hatteras Island population on mainland goods and services.

The southern beaches on Hatteras Island are all part of unincorporated Dare County and feature the six recreational-oriented communities of Rodanthe, Waves, Salvo, Avon, Buxton, and Frisco (see Figure 1-1). Hatteras, a seventh community, is home to the Hatteras Inlet Ferry Terminal. Development in Hatteras reflects its status as a commercial fishing village. A dominant commercial presence exists there along NC 12. Hatteras serves as both a year- round community and a seasonal resort destination. The permanent population on Hatteras Island was 4,001 in 2000.

Products and services involved with daily life on Hatteras Island are transported across the Bonner Bridge. All types of goods can be purchased on the island, but the selection currently is limited, necessitating regular shopping trips north across the Bonner Bridge to Manteo or communities on (Nags Head, Kill Devil Hills, etc). The island residents rely heavily on repair and other services from the mainland. Residents, as well as visitors, of Hatteras Island rely on off-island community services. Telephone and electric service are brought to Hatteras Island via the Bonner Bridge.

On Hatteras Island, the communities of Avon, Buxton, Frisco, and Hatteras are served by the Dare County Water Department. The other Hatteras Island communities of Rodanthe, Waves, and Salvo rely on private wells and the County’s reverse osmosis plant for potable water.

Dare County provides trash collection for the unincorporated areas of Dare County. Refuse is removed from Hatteras Island via the Bonner Bridge. Dare County owns and operates

Bonner Bridge Replacement SDEIS 1-3 NCDOT TIP Project Number B-2500 transfer stations in Buxton and Manteo. On-site septic tank and drainfield systems are the predominant methods of wastewater treatment on Hatteras Island.

Hospitals are in Nags Head, North Carolina; Elizabeth City, North Carolina; Norfolk, Virginia; and Chesapeake, Virginia. Ambulance destinations always are off the island.

• Hatteras Island and Ocracoke Island emergency evacuation requirements.

Visitors and residents rely on NC 12 for evacuation during serious storm events. A 2001 US Army Corps of Engineers (USACE) Hurricane Evacuation Study modeled 2001 evacuation response times (time to move all evacuees through the road network) for North Carolina coastal areas. Clearance times for the North Coastal area (Dare and Currituck Counties) in 2001 ranged from a minimum of 13 hours (Categories 1 – 2 hurricanes, low seasonal occupancy and light background traffic) to a maximum of 33.3 hours (Categories 3 – 5 hurricanes, high seasonal occupancy and heavy background traffic) (Post, Buckley, Schuh and Jernigan, Inc., 2001). The USACE study estimated that for a Category 3-5 hurricane during a period of high occupancy in 2000, 9,530 vehicles could have been expected to evacuate via NC 12 on Hatteras Island.

In 1992, the Dare County Emergency Management Control Group was established to administer the Dare County Emergency Operation Plan. The plan describes evacuation procedures in the event Dare County is evacuated because of the threat of hurricanes or other storm events. An underlying objective of the plan is to minimize physical damage, injury, and loss of life in the event of a hurricane strike. In such an event, the plan provides for Hatteras and Ocracoke islands to be evacuated to Bodie Island via the Bonner Bridge and, subsequently, to the mainland via US 64 and US 158. The Bonner Bridge therefore is considered a critical roadway segment in the plan.

• Travel demand.

The 2002 annual average daily traffic (AADT) volume over the Bonner Bridge was estimated to be 5,400 vehicles per day (vpd). Summer peak season (June through August) daily traffic flows are substantially higher than the AADT. In 2002 during the peak summer season, average weekday traffic crossing the bridge was 8,000 vpd. Average weekend traffic carried in peak season was 10,900 vpd. By 2025, these daily volumes are forecast to rise to 9,600 (AADT), 14,200 (summer average weekday), and 19,200 (summer average weekend).

1.1.2 Migration of the Natural Channel Gorge The Oregon Inlet channel moves. Channel movement must be considered when determining the proper horizontal alignment of any replacement bridge. Since its opening during a storm in 1846, the midpoint of Oregon Inlet has migrated steadily southward just over two miles (3.2 kilometers), for an average rate of 70 feet (21.3 meters) per year. The history of Oregon Inlet's migration is punctuated by alternate widening and narrowing, typically in response to severe storms. Widening and narrowing of Oregon Inlet generally occurs because of erosion and accretion of the Bodie Island (north) shoulder of the inlet. Until construction of the terminal groin in 1989, the Hatteras Island shoulder moved steadily southward. Thus, most of the variation in inlet width is the result of movements of Bodie Island.

Like all active tidal inlets, Oregon Inlet requires periodic dredging to maintain a navigation channel. The current natural inlet gorge is 30 to 40 feet (9 to 12 meters) deep.

Bonner Bridge Replacement SDEIS 1-4 NCDOT TIP Project Number B-2500 1.1.3 Erosion of the Hatteras Island Shoreline Shoreline erosion and ocean overwash threaten to sever segments of the NC 12 roadway for several miles south of Bonner Bridge.

In August 1991, the NCDOT sponsored a research project conducted by North Carolina State University to identify critical sections of North Carolina’s coastal highways and options available for maintaining these highway corridors. The study concluded that NC 12 has six critical sections, or “hot spots,” between Oregon Inlet and the southwestern tip of Ocracoke Island south of Hatteras Island. Three of the hot spots are at the north end of Hatteras Island: Canal Zone, Sandbag Area, and Rodanthe “S” Curve. The NCDOT is conducting environmental and vulnerability studies for each of the six hot spots. They have completed a report (NC 12 Shoreline Erosion Analysis, Canal and Sandbag Areas, 2002) for the two northernmost hot spots, the Canal Zone and Sandbag Area (see Figure 1-1).

The northern Rodanthe area, including the Rodanthe “S” Curve Hot Spot has the highest erosion rates in the Bonner Bridge replacement project area, with a maximum rate of about 15 feet (4.6 meters) per year. Erosion rates in the Canal Zone and Sandbag Area hot spots are as high as 8 feet (2.4 meters) per year. (Overton and Fisher, June 2005)

A partnering agreement to address the long-term needs of NC 12 was formulated and adopted by the USACE, the NPS, the US Fish and Wildlife Service (USFWS), the National Marine Fisheries Service, the Federal Highway Administration, the North Carolina Department of Environment and Natural Resources, Dare County, Hyde County, and the NCDOT. The Executive Committee and Interagency Task Force on the Transportation System on North Carolina’s Outer Banks were established in October 1993 because of the partnering agreement. The Interagency Task Force’s mission is to take an integral role in developing the long-term protection and maintenance plan for the transportation system on the Outer Banks.

In addition, the USACE is conducting a feasibility study of Hatteras and Ocracoke islands, NC to determine possible long-term solutions to the transportation problems that exist on both Hatteras and Ocracoke islands. NCDOT is the local sponsor for this Congressionally authorized feasibility study.

1.2 Project Purpose

The purposes of the proposed project are to:

• Provide a new means of access from Bodie Island to Hatteras Island for its residents, businesses, services, and tourists prior to the end of the Bonner Bridge’s service life.

Needs Addressed: Although Bonner Bridge is reaching the end of its service life, demand for convenient daily and emergency access across Oregon Inlet is expected to continue.

• Provide a replacement crossing that takes into account natural channel migration expected through year 2050 and provides the flexibility to let the channel move.

Needs Addressed: The natural channel or gorge through Oregon Inlet migrates. A replacement bridge needs to provide spans of sufficient height and width for navigation through the anticipated areas of future natural channel migration, helping to reduce future

Bonner Bridge Replacement SDEIS 1-5 NCDOT TIP Project Number B-2500 dredging needs. Construction of the replacement crossing west of Oregon Inlet where less sand movement occurs also could help reduce future dredging needs.

• Provide a replacement crossing that will not be endangered by shoreline movement through year 2050.

Needs Addressed: The southern terminus of Bonner Bridge is north of portions of NC 12 threatened by shoreline erosion and overwash. Placing the southern terminus of a replacement bridge south of these areas or a long-term NC 12 maintenance and protection project will reduce the need for frequency of maintenance of these threatened segments of NC 12.

1.3 Background Information

1.3.1 Project Area Setting and Land Use The Herbert C. Bonner Bridge (Bridge No. 11) spans Oregon Inlet within North Carolina's Outer Banks (see Figure 1-1) and connects Bodie Island with Hatteras Island. (The current Hatteras Island was once two islands: Pea and Hatteras.) The bridge provides the only highway connection of Hatteras Island and the mainland via NC 12 and US 64.

Oregon Inlet is the northernmost inlet along the Outer Banks and is in Dare County. The inlet was opened in 1846 by a severe storm and, after closing, it reopened in 1864. The history of Oregon Inlet has been one of regular migration southward, accompanied by alternate widening and narrowing of the inlet. To maintain navigability of Oregon Inlet, maintenance dredging by the USACE has been necessary since 1960.

Prior to construction of the Bonner Bridge in 1962, transport across Oregon Inlet was via ferry. As demand for transportation across the inlet increased, the ferry was unable to keep pace and the bridge was constructed to meet the demand. The bridge was opened to traffic in November 1963.

During the 2002 summer season, more than 8,700 vehicles crossed the bridge on the average day. The bridge is the only vehicular exit for evacuation from Hatteras Island during major storms. Many residents of Ocracoke Island also evacuate via Bonner Bridge. The bridge also carries the island's electrical power and telephone lines.

The project area includes three types of land use—Cape Hatteras National Seashore, Pea Island National Wildlife Refuge, and the unincorporated community of Rodanthe. Land use in the portion of Rodanthe within the project area includes vacation homes and commercial uses (including an area of junk automobiles, which has been partially cleared, that is associated with an auto parts dealer), a NCDOT emergency ferry dock, a community center, and the Chicamacomico Life Saving Station (a National Register of Historic Places listed historic resource and museum).

1.3.2 Population Growth Dare County is experiencing substantial growth. Forecasts indicate that the population will continue to grow at a rapid rate over the next 20 years. The permanent population of Dare

Bonner Bridge Replacement SDEIS 1-6 NCDOT TIP Project Number B-2500 County was approximately 30,000 in 2000 and is expected to grow to approximately 44,000 by 2020, a 47 percent increase. The 2003 Dare County Land Use Plan indicates that the seasonal population peak for Dare County is approximately 200,000. US Census data for 2000 show that the Hatteras Island permanent population was approximately 4,000.

1.3.3 Project History Since its construction, Bonner Bridge has required continual maintenance. Three major continuing problems requiring periodic maintenance are:

1. Deterioration of the bridge through extensive corrosion of the reinforcing steel and major spalling of concrete on the supporting structures;

2. Scour of a depth great enough to affect the piles’ ability to support the superstructure; and

3. Natural channel migration that results in the periodic need for boat traffic to pass beneath a span adjacent to the bridge’s primary navigation span.

Maintenance projects associated with the correction of these problems began in 1965, when severe scour was discovered near the navigation span, and continue today. In 1978 and 1981, contracts to construct support bents at the Hatteras Island end of the bridge were let in response to a discovery that several bents had pile penetrations of less than seven feet (2.1 meters). In 1989 and 1991, additional piles were installed at the Bodie Island end of the bridge. In 1989 and 1990, a terminal groin (rubble or rock mound structure), projecting 550 feet (167.7 meters) into Oregon Inlet, then turning and extending seaward perpendicular to the shoreline, was built on Hatteras Island to protect the southern bridge approach.

The bridge is also vulnerable to ship collision. This problem became apparent in October 1990. A hopper dredge used to maintain Oregon Inlet’s channel struck Bonner Bridge and demolished several spans. The bridge was not designed to withstand the impact of such a vessel.

A Draft Environmental Impact Statement (DEIS) for the replacement of Bonner Bridge was approved in November 1993. Public hearings were held on February 23 and 24, 1994. A preferred alternative was selected and a preliminary Final Environmental Impact Statement (FEIS) was prepared. Coordination with the USFWS related to Section 7 of the Endangered Species Act was not completed and the FEIS was never finalized nor approved.

Recent trends in shoreline erosion and overwash of NC 12 and other changes in the setting of the project resulted in the decision to prepare this Supplemental Draft Environmental Impact Statement (SDEIS) and assess additional alternatives for the bridge replacement.

An expanded project area that encompasses potential alternative southern termini for the proposed project is shown in Figure 1-1. The project area is within the Cape Hatteras National Seashore, and the portion of the project area south of Oregon Inlet is also within the Pea Island National Wildlife Refuge. The community of Rodanthe is at the southern end of the project area.

Bonner Bridge Replacement SDEIS 1-7 NCDOT TIP Project Number B-2500 1.4 Thoroughfare Planning

1.4.1 Overview of the Thoroughfare Planning Process The thoroughfare planning process is a comprehensive transportation planning process that integrates urban area planning practices with local, regional, and statewide transportation planning practices. The process identifies transportation planning needs by evaluating land development and population growth trends in rural counties and urbanized areas. The process begins through a cooperative effort between the NCDOT’s Transportation Planning Branch and local planning officials. Socio-economic data are collected, including business and residential area inventories, existing street inventories, identification of environmental constraints, and information about the history of the area. A base-year transportation model is built. Utilizing input from local planning officials, land development and population growth trends are projected and applied to the model. Through this modeling process and local knowledge of the area’s socio-economic conditions, the thoroughfare planning team identifies transportation deficiencies and determines short- and long-term solutions for eliminating or diminishing those deficiencies.

1.4.2 Dare County Thoroughfare Plan The Dare County Thoroughfare Plan, last updated in 1988, covers a planning period through 2010. This document is considered out-of-date and is no longer used for transportation planning purposes. (Personal communication, Donna Creef, Dare County Planning Department.) The 1988 plan, however, did list the Herbert C. Bonner Bridge among those bridges considered structurally deficient or functionally obsolete in Dare County. An update to the plan is not currently scheduled.

1.4.3 NCDOT Transportation Improvement Program This project is included as TIP Project No. B-2500 in the NCDOT’s 2006 to 2012 TIP covering the period from Federal Fiscal Year (FFY) 2006 (beginning October 2005) through FFY 2012 (ending September 2012). (Scheduled for Federal Highway Administration approval in October 2005.) The additional transportation projects listed in the TIP that are near the proposed project are depicted in Figure 1-1 and listed below:

Project R-3116 Planning and environmental studies for the long-term maintenance of NC 12 from Ocracoke Island to the southern terminus of Bonner Bridge. A joint NCDOT/USACE feasibility study (Hatteras and Ocracoke islands, NC) is underway.

Project R-3116A Planning for interim measures to protect NC 12 from sand and ocean overwash at Ocracoke Island.

Project R-3116B Planning for interim measures to protect NC 12 from sand and ocean overwash at Hatteras Village.

Project R-3116D Relocate NC 12 from north of Rodanthe to south of Pea Island National Wildlife Refuge Boundary (Rodanthe ‘S’ Curves Hot Spot) to protect roadway from sand and ocean overwash. Planning is in progress. Construction is scheduled for FFY 2007.

Bonner Bridge Replacement SDEIS 1-8 NCDOT TIP Project Number B-2500 Project R-3116E Planning for interim measures to protect NC 12 from sand and ocean overwash at the Sandbag Area Hot Spot

Project R-3116F Planning for interim measures to protect NC 12 from sand and ocean overwash at the Canal Zone Hot Spot

Project R-4070B Planning and environmental studies for maintaining NC 12 from Buxton to Avon. Programmed for planning and environmental studies only.

Project E-4729 Restoration of Chicamacomico Life Saving Station (1874-1954) historic site. Construction scheduled for FFY 2005.

Project S-4004 Enhancement project for scenic beautification to develop a corridor management plan for the Outer Banks (NC 12 and US 70). This project is in progress.

1.5 Transportation Network and Operating Characteristics

1.5.1 Existing Road Network Bridges comprise a key component of the transportation infrastructure and serve as entryways to Dare County. According to the Dare County Land Use Plan (2003), most travel within the County occurs on two arterial routes, NC 12 and US 158. US 158 extends north-south from Southern Shores to the Whalebone area of Nags Head. NC 12 extends north-south from Currituck County to Hyde County on Ocracoke Island. Movements on and off the Outer Banks to the mainland are restricted to US 64 and US 158. Ferry service from Hatteras Village to Ocracoke Island also serves as a means for entering and leaving Dare County.

The Herbert C. Bonner Bridge, which links NC 12 on Hatteras and Bodie islands, provides the only roadway link for travelers driving a vehicle on and off Hatteras Island.

1.5.2 Roadway Characteristics and Posted Speed NC 12 is designated as a major collector route by both the Dare County and the NCDOT Functional Classification Systems. NC 12 is also part of the National Highway System and is classified as an Intermodal Terminal Connector. The NCDOT’s right-of-way for the portion of NC 12 through the Cape Hatteras National Seashore (on Bodie Island) is on a right-of-way that the State of North Carolina retained title to and control of in 1952 when the State deeded land it had acquired for creation of the Seashore to the US Department of the Interior (i.e., the NPS). The NCDOT’s right-of-way for NC 12 through the Pea Island National Wildlife Refuge (on Hatteras Island) is on a permanent easement granted to the State of North Carolina in 1954 by the US Department of the Interior (i.e., the USFWS) for the purpose of “construction, operation, and maintenance of a public road across the Pea Island National Wildlife Refuge.” This easement is granted to the State of North Carolina “so long as it shall continue to use the same for highway right-of-way purposes.” Within the project area, NC 12 is two lanes with unpaved shoulders and

Bonner Bridge Replacement SDEIS 1-9 NCDOT TIP Project Number B-2500 a 60-foot (18.3-meter) right-of-way (except at the north approach to Bonner Bridge, where there is a 100-foot [30.5-meter] right-of-way).

Bonner Bridge is 12,864 feet long (2.44 miles/3,922 meters or 3.9 kilometers), with a navigation span providing 65 feet (19.8 meters) of vertical clearance above mean high tide and 130 feet (39.6 meters) horizontal clearance between fenders. An adjacent span with 90 feet (27.4 meters) of horizontal clearance often is used for navigation as the result of shifting of the natural channel. A 17-foot (5.2-meter) under-clearance at mean sea level is typical for the north and south approaches. The roadway has a 28-foot (8.5-meter) clear roadway with two 12-foot (3.7-meter) lanes and two feet (0.6 meter) of lateral clearance on each side.

The bridge was constructed on a curved alignment that extends across Oregon Inlet 4,000 feet (1,219 meters) inland of the Atlantic Ocean front. The alignment is shown in Figure 1-1. This curved alignment was selected in the early 1960s under the assumption that it would protect the structure from the ocean during storms and because calmer waters facilitated construction. This alignment also allowed large vessels that could not clear the navigational span to find shelter inside Oregon Inlet during storms. The location of the navigation span was selected in anticipation of a jetty stabilization project for the Oregon Inlet, which was to follow the bridge construction by five to ten years. The jetty project was never built. As indicated in Section 1.1, the Bonner Bridge is nearing the end of its service life.

The posted speed limit on NC 12, including Bonner Bridge, is 55 miles per hour (mph) (88 kilometers per hour [kph]), and passing is permitted where sight distances allow.

1.5.3 Sidewalks and Pedestrian Movements There are no sidewalks in the project area. Visitors to the Cape Hatteras National Seashore (Seashore) and the Pea Island National Wildlife Refuge (Refuge) frequently stop on the side of the road to walk over the sand dunes east of NC 12 to reach the Atlantic Ocean. Wildlife trails used by visitors to the Refuge are west of NC 12 near the Refuge Visitor Center and at the Refuge’s southern border. These trails do not cross NC 12. Pedestrians cross NC 12 at Rodanthe to get from vacation homes to the beach, to historic sites, and to commercial recreation facilities and other commercial uses. There are no marked crosswalks in Rodanthe.

1.5.4 Bicycles Two designated bicycle routes cross Oregon Inlet on the Bonner Bridge. A national bicycle touring organization, Bikecentennial, distributes maps and leads tours on the first route, which is a multi- state route from Virginia to Florida. This route, called the North-South Atlantic Coast Bikeway, passes through North Carolina on NC 12 along the Outer Banks, including the Bonner Bridge. The route extends along the East Coast from Maine to Florida and includes most portions of the Wright Brothers Bikeway, currently running from Corolla in Currituck County at its north end, through Dare County, and on to Ocracoke in Hyde County at its south end.

The NCDOT Bicycle and Pedestrian Division also has designated a second route along this portion of NC 12 as part of a loop around Pamlico Sound. Maps of this route are distributed by the Bicycle Program as part of a brochure entitled, "Around Pamlico Sound: Bicycling North Carolina's Outer Banks Region."

Bonner Bridge Replacement SDEIS 1-10 NCDOT TIP Project Number B-2500 1.5.5 Intersections and Access Control There is no access control on NC 12 in the project area. Project area intersections on NC 12 include:

• The driveway to the Oregon Inlet Marina and Fishing Center and the access road to a Seashore campground at the northern end of the project area on Bodie Island;

• The driveway to the parking lot that serves persons who fish off the catwalks mounted on the Bonner Bridge on Hatteras Island near Oregon Inlet;

• Old NC 12 (SR 1257), which is the road that leads to the (former) US Coast Guard Station at the north end of Hatteras Island;

• Periodic parking lots for visitors to the Refuge and the Seashore, including the driveway to the Refuge Visitor Center; and

• Local streets within Rodanthe that serve residential developments and the NCDOT’s emergency ferry dock.

There are no signalized intersections in the project area.

1.5.6 Traffic Volumes

1.5.6.1 Existing Trends (2002) Existing traffic data for NC 12 are available from an automatic traffic counter station (# A2701) at the north end of Bonner Bridge. Traffic volumes collected in 2002 at count station A2701 are summarized in Table 1-1.

The summary data in Table 1-1 show that NC 12 carried an annual average daily traffic (AADT) of 5,400 vehicles per day (vpd) in 2002. As noted in the table, there is a clear distinction between weekend and weekday traffic throughout the year. Weekend traffic is 16 percent higher than the AADT figure with 52.4 percent traveling northbound, reflecting returning tourist traffic traveling to the north. During weekdays, the traffic volume is six percent lower than the AADT figure with a similar pattern of heavier southbound movement or inbound trips.

Table 1-1 also shows the daily traffic volume pattern along NC 12 during the summer months (July and August). As depicted in Figure 1-2, traffic volumes during the summer months are higher than average annual conditions, reflecting a strong seasonal variation in traffic patterns. In 2002, the daily weekend traffic along NC 12 was 73 percent greater than the annual traffic, with volume averaging 10,900 vehicles during summer weekend. For average daily traffic, there are 3,300 additional vehicles (61 percent) on the roadway during the summer season compared to the annual estimate.

The highest daily traffic volume on NC 12 at Bonner Bridge was 14,270 vehicles; this was observed on Saturday, July 6, 2002.

Bonner Bridge Replacement SDEIS 1-11 NCDOT TIP Project Number B-2500 Table 1-1. 2002 Traffic Volumes on NC 12 at the Bonner Bridge

Time Period Northbound (vpd) Southbound (vpd) Total (vpd) Annual Average Daily 2,700 2,700 5,400 Traffic (AADT) (50.0% of total) (50.0% of total) Annual Average 2,500 2,600 5,100 Weekday Traffic (49.0%) (51.0%) Annual Average 3,300 3,000 6,300 Weekend Traffic (52.4%) (47.6%) Summer Average Daily 4,400 4,400 8,800 Traffic (50.0%) (50.0%) Summer Average 3,900 4,100 8,000 Weekday Traffic (48.8%) (51.2%) Summer Average 5,700 5,200 10,900 Weekend Traffic (52.3%) (47.7%) Summer Average 6,400 6,300 12,700 Saturday Traffic (50.4%) (49.6%) 7,900 6,300 Peak Day Traffic 14,200 (55.6%) (44.4%) Notes: • Summer data are based on traffic counts for the months of July and August in 2002. • The peak day was Saturday, July 6, 2002.

Figure 1-2. Comparing Annual and Summer Traffic at Bonner Bridge

12000 73% Increase

10000 58% Increase 61% Increase

8000

6000 VEHICLES PER DAY PER VEHICLES

4000

2000

0 Weekday Weekend Daily

Annual Summer

Bonner Bridge Replacement SDEIS 1-12 NCDOT TIP Project Number B-2500 In addition to high seasonal variation, NC 12 experiences considerable daily variation. This daily variation is depicted in Figure 1-3 for AADT and in Figure 1-4 for the summer peak season. The maximum daily volume spread is 2,340 vehicles, or 49 percent. During the summer peak season, the maximum daily volume spread is 5,500 vehicles (77 percent).

Figure 1-3. Annual Average Daily Traffic by Day of the Week at Bonner Bridge

8000

7000

6000

5000

Southbound 4000 Northbound VEHICLES PER DAY PER VEHICLES 3000

2000

1000

0 Sunday Monday Tuesday Wednesday Thursday Friday Saturday Annual Average

Figure 1-4. Peak Summer Daily Traffic by Day of the Week at Bonner Bridge

14000

12000

10000

8000 Southbound 6000 Northbound VEHICLES PER DAY PER VEHICLES

4000

2000

0 Sunday Monday Tuesday Wednesday Thursday Friday Saturday Summer Average

Bonner Bridge Replacement SDEIS 1-13 NCDOT TIP Project Number B-2500 1.5.6.2 Future Volumes (2025) Projected 2025 traffic volumes are presented in Table 1-2. Future traffic projections were estimated for year 2025 using the uniform growth rate approach. The traffic growth rate was estimated to be 2.5 percent per year. This is consistent with the traffic forecast performed for the 1993 DEIS, as well as NCDOT forecasts for other nearby projects, area population projections, historic traffic growth, area visitor forecasts, and the development potential of available parcels on Hatteras Island.

Table 1-2. 2025 Traffic Volumes on NC 12 at the Bonner Bridge Time Period Northbound (vpd) Southbound (vpd) Total (vpd) Annual Average Daily 4,800 4,800 9,600 Traffic (AADT) Annual Average Weekday 4,400 4,600 9,000 Traffic Annual Average Weekend 5,800 5,400 11,200 Traffic Summer Average Daily 7,700 7,700 15,400 Traffic Summer Average 6,900 7,300 14,200 Weekday Traffic Summer Average 10,100 9,100 19,200 Weekend Traffic Summer Average 11,200 11,100 22,000 Saturday Traffic Peak Day Traffic 14,000 11,200 25,200

1.5.7 Levels of Service Existing and future levels of service (LOS) along NC 12 were estimated based on the two-way, two-lane methodology described in the Highway Capacity Manual (HCM) (Transportation Research Board, 2000).

LOS is a qualitative measure that characterizes the operational conditions within a traffic stream and represents the perception of traffic service by motorists and passengers. The different levels of service characterize these conditions in terms of such factors as vehicle speed, travel time, freedom to maneuver, traffic interruptions, comfort, and convenience. Six levels, represented by the letters A through F, are used to measure level of service. For roadways, LOS A indicates no congestion and LOS F represents more traffic demand than road capacity and extreme delays.

Table 1-3 provides a general description of various levels of service for roadways as given in the HCM, as well as descriptions for signalized and unsignalized intersections. Specific level of service definitions vary for two-lane highways, multi-lane highways, and intersections. In addition, the level of service for signalized and unsignalized intersections cannot be compared directly. In general, a poor level of service rating still can be considered acceptable for an unsignalized intersection. This is because the unsignalized intersection analysis is based upon the delay for minor street drivers as they await sufficient gaps in major street traffic. The signalized intersection analysis provides an overall average delay and level of service for the entire intersection.

Bonner Bridge Replacement SDEIS 1-14 NCDOT TIP Project Number B-2500

Table 1-3. Level of Service Criteria

Level of Delay at Signalized Delay at Two-Way Traffic Flow on Roadways Service Intersection Stop Intersection Free flowing traffic with little or no A <= 5 sec <=5 sec delays. A stable flow with few congestion- B 5-15 sec 5-10 sec related restrictions on operating speed. Stable flow but with more restrictions on C 15-25 sec 10-20 sec speed and changing lanes. Approaches unstable conditions and passing becomes extremely difficult. D 25-40 sec 20-30 sec Motorists are delayed an average of 75 percent of the time. The capacity of a roadway. Passing is virtually impossible, speeds drop when E 40-60 sec 30-45 sec slow vehicles or other interruptions are encountered. Heavily congested flow with traffic F demand exceeding the capacity of the >60 sec >45 sec highway.

Traffic operations on two-lane, two-way roadways are subjected to lane changing and passing in the opposing lane. As a result, the HCM approach uses a passing capacity that is dependent on the peak-hour traffic volume in both directions of travel. Consequently, LOS for a two-lane roadway is defined based on two primary measures. These are:

• Average travel speed; and

• Average percentage of travel time that vehicles must travel in platoons (groups of vehicles) behind slower vehicles because of the inability to pass those slow vehicles (percent time- spent-following).

A traffic capacity analysis was performed for two roadway types and locations encountered within the project area. One location was on Hatteras Island south of the bridge, and the other was on the Bonner Bridge structure. Although the traffic volumes are nearly identical for the two locations, it is necessary to analyze both cases separately because of their unique operational characteristics and geometric differences. These differences include shoulder widths, percent no passing zones, and access points per mile, which affect average travel speed and percent time- spent-following. Table 1-4 details these differences, as well as other key inputs assumed for the capacity analysis.

Bonner Bridge Replacement SDEIS 1-15 NCDOT TIP Project Number B-2500 Table 1-4. Highway Capacity Analysis Variable Comparison

Analysis Variable Mainland Bonner Bridge Shoulder Width 8 feet (2.4-meters) 2 feet (0.6-meters) Lane Width 12 feet (3.7-meters) 12 feet (3.7-meters) Highway Class II II Directional Split 60% 60% Peak Hour Factor 0.88 0.88 Truck Percentage 6% 6% % No Passing Zone 20% 50% Access Points Per Mile 2 0

Table 1-5 shows a summary of existing and future LOS for Bonner Bridge during five time periods:

1. Average Weekday;

2. Average Weekend;

3. Peak Season Weekday;

4. Peak Season Weekend; and

5. Peak Season Saturday.

Table 1-5. Level of Service (LOS) on the Bonner Bridge

Peak Hour Traffic Average Percent Time- Time Period Volume Travel Speed Spent- LOS (vehicles per (mph) Following hour [vph]) EXISTING (2002) Average Weekday 450 50.3 54.9% B Average Weekend 600 49.6 60.0% C Peak Season Weekday 690 49.1 61.9% C Peak Season Weekend 1030 46.8 72.6% D Peak Season Saturday 1180 45.8 76.0% D FUTURE (2025) Average Weekday 790 48.4 65.4% C Average Weekend 1060 46.6 73.4% D Peak Season Weekday 1210 45.6 76.7% D Peak Season Weekend 1810 40.6 86.9% E Peak Season Saturday 2080 38.2 89.9% E

Bonner Bridge Replacement SDEIS 1-16 NCDOT TIP Project Number B-2500

Similarly, Table 1-6 and Figure 1-5 show the existing and future LOS for the NC 12 roadway segment immediately south of the Bonner Bridge.

Table 1-6. Level of Service (LOS) on NC 12 South of Bonner Bridge

Peak Hour Traffic Average Percent Time- Time Period Volume Travel Speed Spent- LOS (mph) Following (vph) EXISTING (2002) Average Weekday 450 53.6 49.0% B Average Weekend 600 52.6 55.1% C Peak Season Weekday 690 52.0 57.8% C Peak Season Weekend 1030 49.5 69.5% C Peak Season Saturday 1180 48.4 73.3% D FUTURE (2025) Average Weekday 790 51.2 61.6% C Average Weekend 1060 49.3 70.3% D Peak Season Weekday 1210 48.1 74.1% D Peak Season Weekend 1810 42.9 85.8% E Peak Season Saturday 2080 40.5 89.0% E

Table 1-5 shows that Bonner Bridge operates at an unstable flow condition (LOS D) during peak summer weekend because motorists are delayed in platoons for nearly 73 percent of their travel time, as passing becomes extremely difficult. This peak summer weekend condition is projected to worsen to LOS E by 2025, when passing would be virtually impossible and platooning would increase. By 2025, Bonner Bridge is also projected to operate at LOS D, with an extremely difficult passing environment during a peak summer weekday or an average weekend.

Table 1-6 shows that NC 12 south of Bonner Bridge is projected to operate at similar LOS conditions by 2025, but with slightly less platooning and a higher travel speed than on Bonner Bridge.

1.5.8 Crashes In the period from November 1, 1999, to October 31, 2002, 50 crashes were reported along the 18-mile (29.0-kilometer) NC 12 corridor from north of the Oregon Inlet Marina and Fishing Center driveway intersection on Bodie Island to the southern limits of Rodanthe on Hatteras Island. Five of these crashes occurred on Bonner Bridge. A summary of crash rates on NC 12, both on the bridge and south of the bridge, is depicted in Table 1-7. The table also presents a comparison of Bonner Bridge crash rates with similar roadways in NCDOT’s Division 1, the state, and the nation.

Bonner Bridge Replacement SDEIS 1-17 NCDOT TIP Project Number B-2500 Roanoke Sound

Cape Hatteras National Seashore Broad Creek ATLANTIC OCEAN 345 12

WANCHESE Bodie Island

Roanoke Island N 2002 (Weekday) - LOS C Duck 2002 (Weekend) - LOS D Island 2025 (Weekday) - LOS D 2025 (Weekend) - LOS E

Canal Zone Bonner Cap Bridge Hot Spot e Ha

tt Oregon Inlet er a s National

S e a Pamlico Sound 12 s h ore Sandbag Area Pea Island Hot Spot National Wildlife Refuge

2002 (Weekday) - LOS C 2002 (Weekend) - LOS C 2025 (Weekday) - LOS D 2025 (Weekend) - LOS E 12

Hatteras Island Rodanthe 'S' Curves Hot Spot

Emergency RODANTHE 0 1 2 KM Ferry Dock

0 1 2 Miles

Figure PEAK SEASON LEVEL OF SERVICE 1-5 Table 1-7. Crash Rate Trends

Crashes per 100 Million Vehicle Miles/Kilometers (MVM/K)

Crash Type NC 12 at NC 12 Between NCDOT North United Bonner Bodie Island 2 3 4 Division 1 Carolina States Bridge1 and Rodanthe1

Total 46.40/74.24 62.06/99.30 124.16/198.66 186.06/297.70 237/379.20

Fatal 0.00/0.00 0.00/0.00 2.00/3.20 2.41/3.86 1.4/2.24

Non-Fatal Injury 18.56/29.70 23.58/37.73 48.42/77.47 79.8/127.68 77/123.20

Night 0.00/0.00 14.89/23.82 49.31/78.90 61.64/98.62 63/100.80

Wet Surface 18.56/29.70 12.41/19.86 21.7/34.72 32.03/51.25 NA5

Equivalent NA 321.46/514.34 NA NA NA Property Damage

1 NCDOT, Traffic Engineering Accident Analysis System, Strip Analysis Report, November 1, 1999 through October 31, 2002. 2 NCDOT, Traffic Engineering Accident Analysis System, 1999–2001 Three Year Crash Rates for Highway Division #1 (for rural NC routes only). 3 NCDOT, Traffic Engineering Accident Analysis System, 1999–2001 Three Year Crash Rates (Standard) (for rural NC routes only). 4 U.S. Department of Transportation, National Highway Traffic Safety Administration, Traffic Safety Facts 2000 (for all routes). 5NA=Not Available.

The Bonner Bridge and NC 12 crash rates (46.40 [74.24] and 62.06 [99.30] crashes per 100 million vehicle miles [kilometers], respectively) were found to be well below the average rates observed in NCDOT’s Division 1, statewide, and nationwide.

The crash rates for NC 12 and Bonner Bridge were calculated based on 50 crashes that have been reported during between 1999 and 2002. A detailed look at these 50 crashes reveals the following pattern:

• 56 percent of the crashes occurred during the summer months (June, July, and August);

• 62 percent of the crashes occurred on Friday, Saturday, or Sunday; and

• 48 percent of the crashes were rear-end collisions.

Table 1-8 contains a full list of the crash types.

Bonner Bridge Replacement SDEIS 1-19 NCDOT TIP Project Number B-2500 Table 1-8. Type of Crashes on NC 12

Number of Crashes Crash Type Percent of Total (1999-2002) Angle 1 2% Animal 7 14% Head On 1 2% Left Turns 2 4% Ran Off Road 7 14% Rear End 24 48% Right Turns 1 2% Sideswipe 3 6% Other 4 8% Total 50 100%

Figure 1-6 provides an indication of how crashes are distributed along NC 12 in the project vicinity. The majority of the crashes were scattered along the approximately 18-mile (29.0- kilometer) corridor, however, the highest frequency of the crashes (20) occurred near Rodanthe.

The following are the four spots along NC 12 that experienced three or more crashes:

• South of Sea Oats Drive – five crashes;

• SR 1428 (Atlantic Road) – four crashes;

• SR 1292 (Trade Winds Drive) – four crashes; and

• SR 1256 (Old NC 12) – three crashes.

1.5.9 Hurricane Evacuation The residents and visitors of Hatteras Island and Ocracoke Island, two hurricane-prone coastal communities in North Carolina, travel on NC 12 and across Bonner Bridge when evacuating the area during a storm warning. Consequently, the Bonner Bridge serves an important function in emergency evacuation and helps reduce the clearance time (i.e., time to evacuate all participating population during a hurricane storm).

The evacuation clearance time depends on the following key emergency planning variables:

• Type of hurricane storm (Categories 1 – 5, see Table 1-9);

• Tourist Season (peak season with high occupancy vs. off-peak season with low occupancy);

• Location and number of people living in permanent occupied units, mobile home units and seasonal tourist units;

Bonner Bridge Replacement SDEIS 1-20 NCDOT TIP Project Number B-2500 Roanoke Sound

Cape Hatteras National Seashor Br oad Cr A 345 12 eek TLANTIC OCEAN

WANCHESE Bodie Island

e 6 Crashes N

Duck Island 5 Crashes

Bonner C Bridge ap e Ha 7 Crashes

egon Inlet tte Or ras Na

tion

a l Pea Island S e a Pamlico Sound National Wildlife 12 s h Refuge or e 7 Crashes

5 Crashes

12

Hatteras Island 20 Crashes

0 1 2 KM RODANTHE 0 1 2 Miles * NCDOT Three Year Crash Report (11/99 - 10/02)

Figure REPORTED CRASHES IN PROJECT AREA 1-6 Table 1-9. Hurricane Categories1 Storm Type Wind Speed Damage Potential Category 1 (Weak) 74 – 95 mph (118 – 153 kph) Minimal damage to vegetation Category 2 (Moderate) 96 – 110 mph (154 – 177 kph) Moderate damage to houses Extensive damage to small Category 3 (Strong) 111 – 130 mph (178 – 209 kph) buildings Category 4 (Very strong) 131 – 155 mph (210 – 247 kph) Extreme structural damage Catastrophic building failures Category 5 (Devastating) > 155 mph (> 248 kph) possible 1 Hurricanes are rated in intensity on the Saffir-Simpson Hurricane Scale based on wind speed, pressure, storm surge, and damage potential. This list from the Federal Emergency Management Agency provides a basic description.

• Rates of participation in the evacuation;

• Origin and destination of the evacuation trip;

• Use of vehicles; and

• Service capacity of the critical roadway links along major evacuation routes.

The above emergency planning variables were used to develop a Hurricane Evacuation Model for the USACE’s Wilmington District in 2001. The model automated the steps involved in calculating clearance times for different storm types during the peak and off-peak tourist seasons. The Hurricane Evacuation Model uses demographic data from the 2000 Census, which can be updated to a future year.

Year 2025 modeling results for the Hatteras and Ocracoke islands are presented in Table 1-10 for Categories 1 – 2 and Categories 3 – 5 storm types. The table shows that there would be approximately 14,761 evacuating vehicles on Bonner Bridge in response to a Category 3 – 5 storm during the peak tourist season in 2025.

Table 1-10. Year 2025 Hurricane Evacuation Analysis by Zones Evacuating People Evacuating Vehicles Evacuation Zone Off-Peak Peak Tourist Off-Peak Peak Tourist Tourist Season Season Tourist Season Season CATEGORY 1–2 HURRICANE Hatteras Island 17,152 38,165 5,679 12,246 Ocracoke Island 1,979 4,832 724 1,723 Total 19,131 42,997 6,403 13,969 CATEGORY 3–5 HURRICANE Hatteras Island 19,249 40,262 6,471 13,038 Ocracoke Island 1,979 4,832 724 1,723 Total 21,228 45,094 7,195 14,761

Bonner Bridge Replacement SDEIS 1-22 NCDOT TIP Project Number B-2500 1.6 Modal Interrelationships

1.6.1 Railroads Railroad service is not available in Dare County.

1.6.2 Airports Dare County Regional Airport is a publicly owned, general aviation airport in Manteo on Roanoke Island, outside the project area. The airport is capable of serving most regional jets.

There are three publicly owned airstrips for private aircraft on the Outer Banks, but not within the project area. One is further north in Kill Devil Hills. The other two are further south on Hatteras and Ocracoke islands. Each airstrip is owned and managed by the NPS and operates during daylight hours only.

No commercial passenger or freight air service is available in the project area.

1.6.3 Transit There is no local or regional bus service provided in the project area. Taxi service is available. Para-transit services are provided by Dare County to serve elderly and handicapped persons.

1.6.4 Water Travel (Ferry) Six vessels operate between the southern end of Hatteras Island and Ocracoke Island across Hatteras Inlet. In 2000, more than 25,800 ferry trips carrying 989,435 travelers were made between the two islands. On Ocracoke Island, ferry service is provided south to Cedar Island and Swan Quarter on the Hyde County mainland. Ferry schedules are designed to accommodate expected vehicular demand, which is highest in the summer months. Emergency ferry landings are at Rodanthe on Hatteras Island and at Stumpy Point on the mainland. These would be used by ferries if access to Hatteras Island by the Bonner Bridge were to be disrupted.

1.7 Summary

The North Carolina Department of Transportation’s 2006 to 2012 TIP includes the replacement of the Herbert C. Bonner Bridge (Bridge No. 11) over Oregon Inlet in Dare County (TIP Project No. B-2500). The need for a crossing of the Oregon Inlet will continue past the end of the service life of Bonner Bridge. Continued demand for convenient daily and emergency access across Oregon Inlet is expected. The natural channel or gorge through Oregon Inlet migrates. A replacement bridge needs to provide spans of sufficient height and width for navigation through the anticipated area of future natural channel migration, helping to reduce future dredging needs, dredging impacts, and the cost of dredging. The southern terminus of Bonner Bridge is north of parts of NC 12 that are frequently threatened by shoreline erosion and overwash. Placing the southern terminus of a replacement bridge at Rodanthe or implementing a long-term NC 12 maintenance project between Rodanthe and Oregon Inlet will eliminate regular maintenance of NC 12 in this part of Hatteras Island.

Bonner Bridge Replacement SDEIS 1-23 NCDOT TIP Project Number B-2500