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Report to Congress on the 14th Amendment Highway Corridor

Table of Contents


This Report to Congress presents the major findings associated with the estimated costs and steps necessary to designate and construct a continuous route for the 14th Amendment Highway Corridor, linking Natchez, Mississippi; Montgomery, Alabama; and Columbus, Macon and Augusta, Georgia, and is submitted pursuant to Section 1927 of Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU).

The 14th Amendment Highway, as defined by the above listed cities that constitute the statutorily designated service points, is over 600 miles long and passes through predominantly rural sections of Mississippi, Alabama, and Georgia. Although several major Interstate highways pass through the corridor, they are all generally oriented in a north-south direction; there is no single designated east-west Interstate or other major highway that directly connects all five cities.
Five different conceptual corridor alignment/design alternatives were evaluated for the 14th Amendment Highway, ranging from one that would utilize existing highways to the maximum extent feasible to one that would be composed of roads built to Interstate design standards involving substantial amounts of new location roadway construction on new rights of way. The alternatives are defined along two dimensions – highway design level and route alignment. An alternative may utilize more than one design level for different parts of its alignment. Conversely, two alternatives may follow the same route alignment, but have different costs because their design levels differ.
In identifying alternative conceptual alignments for the 14th Amendment Highway, priority consideration was given to utilizing existing highways to the maximum extent possible. The study identified several significant highway projects located in the Corridor that are currently either under construction or designated in specific State Transportation Improvement Programs (STIP). All planning and construction costs associated with these projects were excluded from the cost estimates. These highway projects include:

Figure 1 illustrates the general alignments for the five alternatives.

Figure 1 shows the five alternative alignments crossing the states of Mississippi, Alabama and Georgia.  Each alternative is color coded and shows the connection of the five control points.  The control points shown are Natchez, Mississippi; Montgomery, Alabama; Columbus, Georgia; Macon, Georgia; Augusta, Georgia.

Figure 1. 14th Amendment Highway - Alternative Alignments

Alternative 1 represents the all Interstate design. It would require upgrading approximately
97 miles of existing roads to full Interstate design standards, and the construction of over
178 miles of additional four-lane limited access highways built to Interstate design standards on new rights-of-way (ROW). This would require a total of approximately 275 miles of new construction or the upgrading of existing routes, with the remaining 325 miles of the corridor representing the use of existing Interstate highway facilities.

Alternative 2 utilizes existing highways to the maximum extent feasible. It would require no significant amounts of new ROW acquisition, but would upgrade approximately 17 miles of existing two-lane rural roads to provide a basic four-lane highway cross section. Some sections of this alternative, primarily through small urban areas, would remain as urban arterials with no access control and the use of a center, two-way left-turn lane instead of a raised traffic median.

Alternative 3 would upgrade existing roads to current State department of transportation (DOT) and American Association of State Highway and Transportation Officials highway design standards where practical, with a minimum of two travel lanes in each direction, a variable width center median, and grade-separated interchanges at all intersections with the United States (U.S.) and State numbered routes. It would require construction of approximately 4 miles of new highway bypass routes on new ROW, and would upgrade approximately 18 miles of existing two-lane roads to provide a basic four-lane highway cross section.

Alternatives 4 and 5 represent two different conceptual corridor alignments between Natchez, Mississippi, and Montgomery, Alabama. Both options would follow the same alignment as Alternative 3 from Montgomery to Augusta, Georgia. The alignment of Alternative 4 would follow US 84 from Natchez to its intersection with I-65 near Evergreen, Alabama. It would require construction of approximately 4 miles of new highway on new ROW, and would upgrade approximately 118 miles of existing two-lane roads, primarily along portions of US 84 in Alabama. Alternative 5 also follows US 84 from Natchez to near Grove Hill, Alabama, but then would construct a new highway on its own ROW between Grove Hill and I-65, near Greenville, Alabama. This alternative would require construction of approximately 69 miles of new highway and would upgrade 65 miles of existing two-lane roads.

Costs for each alternative were calculated using standard Federal Highway Administration (FHWA) cost estimating procedures and a consistent set of assumptions with respect to ROW requirements, design specifications, and construction techniques. Table 1 presents the resulting estimated cost range for each of these conceptual corridor level alternatives.

Table 1. Total Project Costs by Alternative


Total Estimated Cost
($ Million)

Alternative 1 (All Interstate) $6,612 - $7,656
Alternative 2 (Maximum Use of Existing Highways) $296 - $343
Alternative 3 (Highway Utilizing US 84 to I-59 at Laurel, MS) $1,402 - $1,623
Alternative 4 (Highway Utilizing US 84 to I-65 at Evergreen, AL)* $2,999 - $3,473
Alternative 5 (Highway Utilizing US 84 to I-65 at Greenville, AL)* $3,322 - $3,847

Note: Alternatives 4 and 5 follow the same alignment as Alternative 3 from Montgomery to Augusta.

Alternative 1, which would construct the entire 14th Amendment Highway Corridor to full Interstate highway design standards, is estimated to cost between $6.6 - $7.6 billion, more than double the cost of the next most expensive alternative. By contrast, Alternative 2, which would utilize existing highways to the maximum extent practical, is estimated to cost between
$296 - $343 million, or about 5 percent of the cost of an all Interstate design. Alternative 2 would still require upgrades to some existing two-lane sections of rural roads, but would leave some sections through urban areas as four-lane urban arterials. Alternatives 3, 4, and 5 would provide additional improvements to existing highways, including grade-separated interchanges on rural sections, and construction of bypass routes around some urban areas. Estimated costs for these improvements range from $1.4 - $3.8 billion.

The steps required to construct any of the alternatives for the 14th Amendment Highway are similar. Alternatives could (and most likely would) be broken out into smaller projects such as new roadway alignments, new interchanges, widening of existing roadways, or intersection improvements. Any project involving the potential expenditure of Federal-aid highway funds in association with its planning, design, or construction would need to be included in each State's long-range transportation plan (LRTP) and STIP. Projects which pass through any of the eight metropolitan planning organization (MPO) planning areas along the corridor would also have to be included in the respective MPO's long-range metropolitan transportation plan and transportation improvement program (TIP).

Each project would have to obtain a variety of required Federal, State and local approvals. The number and complexity of the approval process would vary with each project, depending on such factors as the amount and location of new ROW; proximity of the highway improvements to environmentally sensitive areas such as wetlands, parklands, other protected areas, historic and cultural sites, and navigable waterways; and potential impacts of the highway improvements on traffic volumes, noise levels, mobile source air quality, etc. Approved projects would be designed, engineered, and constructed to Federal Standards and according to the contractual procedures established by each State DOT.

This study was conducted to conform to the specific requirements of the statute which focused on the definition of cost estimation and identifying those general steps required to complete construction of a single continuous route to link the specified communities. If this project were to move forward, additional studies including travel demand forecasts, analyses of economic development impacts, environmental impacts (where new ROW is involved or major physical changes to the existing facilities are required), safety improvements, and benefit/cost analyses would be required to support the approval processes described above. The additional studies are discussed in a separate report to FHWA on recommendations for selected sub-studies for the 14th Amendment Highway.

Stakeholder outreach for this study was conducted primarily through an Expert Working Group (EWG) which consisted of 21 representatives from interested public agencies in the corridors including State DOTs, MPOs, and Federal transportation and resource agencies. The EWG met four times during the course of the study and reviewed and commented on all study material. Briefings were conducted by the study team at meetings held in each of the five designated study cities, plus the Auburn-Opelika urbanized area in Alabama, and a publicly available Webcast was conducted on June 8, 2011.

Seven technical memoranda were produced in support of the study. They can be found at the project Web site at

Section 1927 also authorized a second study to describe the steps and estimated funding necessary to designate and construct a route for the proposed 3rd Infantry Division Highway from Savannah, Georgia to Knoxville, Tennessee, by way of Augusta, Georgia. This second study is the subject of a separate Report to Congress.

Updated: 1/31/2017
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