Task 7 Study Alignments and Design Levels Draft Technical Memorandum
Appendix A: Preliminary Corridors
At the second meeting of the EWG in December 2010, the project team presented the illustrative corridors depicted on Figures A-1 and A-2. The corridors were used to facilitate discussion among EWG members on the range of study alignment corridors. EWG members also identified potential issues to be considered in the corridor evaluation process. Based on the scope of work, at least four alignment alternatives are to be developed between Savannah and Lavonia; five alignment alternatives are to be developed between Lavonia and Knoxville. At least one of the alignments for each segment is required to meet Interstate design standards and at least one alignment for each segment should follow substantial portions of existing roadways.
Four illustrative corridors were identified by the project team between the Savannah and Augusta Control Points:
|Savannah to Augusta
||Description (see Figure 2)
||Northward from I-16 east of Savannah, passing through Swainsboro, Louisville, and Thomson to reach I-20 west of Augusta; generally follows the existing US 1/SR 17 corridor
||Northward along Savannah River Parkway from I-16, passing through Statesboro, Millen, and Waynesboro, to I-520 in southern Augusta; generally follows the existing US 25 corridor
||Northwest from Savannah, passing near Sylvania and east of Waynesboro, to I-520 in southern Augusta; primarily along new alignment
||Northwest from I-95 north of Savannah and east of Savannah River Parkway to I-20 east of Augusta; combination of new and existing roadways
Five illustrative corridors were identified between the Augusta and Knoxville Control Points:
|Augusta to Knoxville
||Description (see Figure 3)
||Northwest through Georgia from I-20 at Thomson, east of Athens, across I-85 near Commerce, westward along the southern boundary of the Chattahoochee National Forest to I-75 at Dalton, Georgia
||Through Georgia northwest from I-20 west of Augusta, passing Washington and Elberton, crossing I-85 near Lavonia, northwest through the National Forests near Georgia/Tennessee/North Carolina boundary to I-75 north of Cleveland, Tennessee
||Through Georgia northwest from I-20 west of Augusta, passing Washington and Elberton, crossing I-85 near Lavonia, northwest through the National Forest lands near Chatuge Lake and the western boundary of Great Smoky Mountains National Park to I-140 in Knoxville
||Through Georgia northwest from I-20 west of Augusta, passing Washington and Elberton, crossing I-85 near Lavonia, northward through the Great Smoky Mountains National Park on US 441 to I-140 in Knoxville
||Northwest from northern Augusta, through South Carolina west of Greenville and Asheville, past the eastern edge of the Great Smoky Mountains National Park to I-40 near Newport, Tennessee
EWG members offered a number of comments regarding sensitive resources that should be considered during the corridor development process. Their input is summarized below.
- Corridors should avoid National Forest lands. National Forests are identified in each of the four states in the General Study Area, generally concentrated at the northern end. Forests include Sumter Forest (SC), Chattahoochee Forest (GA), Nantahala Forest (NC), Pisgah Forest (NC), and Cherokee Forest (TN).
- Corridors should avoid federally designated Wilderness Areas, which are stringently protected from development and cannot be removed from the system without a Congressional designation. A number of these Congressionally-designated areas exist in the northern portion of the General Study Area: Joyce Kilmer-Slickrock, Citico Creek, Bald River Gorge, Gee Creek, Little Frog Mountain, Big Frog, Cohutta, Rich Mountain, Shining Rock, Middle Prong, Southern Nantahala, Ellicott Rock, Brasstown, Mark Trail, Tray Mountain, and Raven Cliffs.
- Corridors should avoid the Great Smoky Mountains National Park. Existing routes through the park face periodic closures during inclement weather; commercial traffic is prohibited from traveling through the park by federal legislation.
- Corridors should avoid National Wildlife Refuges. There are a number of national refuges in the study area, concentrated around Savannah: Tybee NWR, Savannah NWR Complex, and Wassaw NWR.
- Corridors should avoid critical endangered species habitats. Critical Carolina Heelsplitter habitat exists in South Carolina. There are bear reserves in the northern portion of the General Study Area and a large Indiana Bat hibernaculum in Tennessee. The Great Smoky Mountains National Park is home to 10 different federally protected species.
- Much of the northern portion of the study area is subject to topographic and geologic concerns: mountain ranges above 5,000 feet, pyritic rock, and areas susceptible to landslides.
- Corridors should avoid the Savannah Nuclear Station in Barnwell and Aiken Counties, SC.
- Corridors should avoid major river crossings that would require new structures. There are several large lakes, rivers, and streams in the General Study Area, including three Wild and Scenic Rivers: Chattooga River, Horsepasture River, and Wilson Creek.
- A special cross-section should be developed for segments in sensitive areas, similar to the I-70 tunnel sections near Denver or the elevated viaducts along the Blue Ridge Parkway.
- All potential corridors should be developed before any are eliminated, for example, a link that provides access to Atlanta. Any eliminated corridors will require supporting justification.
Other sensitive features, not specifically identified by the EWG, include the Eastern Band of Cherokee Indians Reservation, Historic Districts and Landmarks, population centers, environmental justice communities, and state/local parks. These and other constraints to highway development are discussed later in this document.
After reviewing the Illustrative Corridors described above, EWG members offered specific recommendations about routing for the corridors. Input from the EWG is summarized below.
- Corridors should follow existing roadway alignments as much as possible; however, improvements along existing roadway will affect existing developments.
- Existing I-40 is not a suitable corridor for improvements because it experiences frequent traffic delays (especially around Asheville) and is prone to landslides. Alternatively, these are reasons suggested by other EWG members to improve the route; a single expenditure of public funds can alleviate landslide potentials, provide additional truck climbing lanes, replace some sections with viaducts, and fulfill the desire to create a 3rd Infantry corridor.
- Corridors that connect to I-75 are preferable to connections to I-40.
- The Savannah River Parkway experiences congestion from I-95 north to Rincon; this corridor should be avoided. Corridors should consider following the parkway between Millen and Savannah. Completion of this route may satisfy the intent of the 3rd Infantry Corridor legislation.
- Existing I-26 into Asheville is not a suitable corridor for improvements because it is heavily congested and is likely to result in controversy.
- Existing I-40 is not suitable between Asheville and Knoxville because of its terrain, specifically passing through Pigeon River Gorge.
- Corridors should consider following existing routes from Augusta east to I-26, for example, traveling along SR 121.
- Corridors should consider following US 441/Newfound Gap Road through the Great Smoky Mountains National Park instead of building on a new alignment.
- A corridor should be developed along the planned Governor's Bond freight corridor from Savannah to the Jimmy Deloach Parkway.
- A corridor should be developed that follows the railroad corridor north out of Savannah.
- A link should be considered along US 78 between Illustrative Corridors 1 and 2.
- A corridor that follows SR 21 or SR 17 to Millen or SR 305 to Louisville would be consistent with the 14th Amendment study corridor.
Illustrative Corridor 4 should be relocated from US 441 into North Carolina to follow existing four-lane sections.