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Successes in Stewardship
Monthly Newsletter
March 2008

Section 4(f) Final Rule: New Guidance on a Complex Regulation

This picture shows Fort McHenry, a historic site that was protected by Section 4(f) from having a suspension bridge built in its sightline.
Under Section 4(f) requirements, when a proposed suspension bridge was found to pose the possibility of adverse impacts to Fort McHenry, the historical site where Francis Scott Key penned "The Star- Spangled Banner," planners revisited the alternatives and chose to build a tunnel under the Baltimore Harbor instead. (Photo courtesy of the National Park Service)

Section 4(f), the statute that protects public parks, recreational areas, wildlife and waterfowl refuges, and public and private historical sites from use by proposed transportation projects, is one of the most stringent environmental laws related to transportation. Its requirements involve judgments that elude easy explanation and are often difficult to interpret with a great deal of confidence. As a result, Section 4(f) has become the most frequently litigated environmental statute in the Federal Highway Program aside from the National Environmental Policy Act (NEPA). It is also the most frequent cause of court injunctions delaying highway projects.1 If Section 4(f) compliance becomes an issue during the preparation of an Environmental Impact Statement (EIS), project approval can take additional time.

On March 12, 2008, the Federal Highway Administration (FHWA) and Federal Transit Administration (FTA) published a Section 4(f) Final Rule in the Federal Register to help clarify the 4(f) approval process and simplify its regulatory requirements. This month's newsletter provides a first look at the Final Rule, highlighting key changes made to the 4(f) regulation as required by Section 6009 of the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU).

Background to Section 4(f)

Established in the U.S. Department of Transportation Act of 1966, Section 4(f) was designed to protect publicly owned parks, recreational areas, wildlife and waterfowl refuges, and public and private historical sites from use by transportation projects unless the Administration determines that there is no "feasible and prudent" avoidance alternative and that all possible planning to minimize harm" has occurred. Section 4(f) originated during the peak period of Federal highway construction with the goal of preserving urban parks and historical sites that were in jeopardy of being destroyed.

Early case law strictly interpreted what qualified as a "feasible and prudent" avoidance alternative. In its 1971 Overton Park decision2 , the U.S. Supreme Court articulated a very high standard for compliance with Section 4(f). In the years that followed, however, courts applied the Overton Park ruling differently in similar situations, reaching diverse conclusions about the extent to which certain mitigating factors may be considered in determining whether or not an avoidance alternative is "feasible and prudent."

Two important changes to the Section 4(f) process occurred in 2005 in connection with Section 6009 of SAFETEA-LU. First, the process for approving projects that will have de minimis impacts on property protected by Section 4(f) was simplified. The analysis of avoidance alternatives is no longer required when a transportation use of a Section 4(f) property is determined to have a de minimis impact. Second, the Secretary of Transportation was directed to clarify which factors to consider and which standards to apply for determining the "prudence and feasibility" of alternatives that avoid the use of Section 4(f) property.

In response to SAFETEA-LU's directive, FHWA and FTA published a Notice of Proposed Rulemaking (NPRM) containing modifications to the existing 4(f) regulations on July 27, 2006. The NPRM received 37 responses from state and regional transportation agencies, trade associations, national and environmental advocacy groups, Federal agencies, a state historical preservation officer, and two members of the public. After carefully considering all of the submitted comments, FHWA and FTA published their Final Rule, Title 23 of the Code of Federal Regulations (CFR), Part 774: Parks, Recreation Areas, Wildlife and Waterfowl Refuges, and Historic Sites (Section 4(f)), in the Federal Register on March 12, 2008. The new rule will govern all 4(f) approvals granted as of the effective date.

Structure of the New Section 4(f)

774.3Section 4(f) Approvals
774.15Constructive Use Determinations

Introducing the Final Rule: 23 CFR Part 774

While Section 4(f) remains codified in law at Title 49 United States Code (USC) § 303 and 23 USC § 138, the regulation implementing this law has been moved from 23 CFR 771, FHWA's NEPA implementation regulation, to 23 CFR 774, in order to highlight that Section 4(f) is one of numerous social, economic, and environmental issues that must be considered under the "umbrella" of the environmental review process. In addition to being assigned a new location, the regulation has been reorganized to improve clarity and readability (see sidebar).

While a number of sections, such as "Timing" and "Constructive Use Determinations," remain largely unchanged, the Final Rule makes five principal changes to the Section 4(f) regulation:
  1. Defines "feasible and prudent": The Final Rule defines a "feasible and prudent" avoidance alternative as one that "avoids using Section 4(f) property and does not cause other severe problems of a magnitude that substantially outweighs the importance of protecting the Section 4(f) property." The definition emphasizes that the use of Section 4(f) property is to be balanced against competing factors, with a "thumb on the scale" in favor of preserving the Section 4(f) property. The competing factors must pose the threat of severe problems or impacts. The definition describes an alternative as not feasible if it cannot be constructed on the basis of sound engineering judgment. A list of factors with a severity that may rise to the level at which an alternative would qualify as "not prudent" is included. The definition of feasible and prudent is located in section 774.17.

  2. Outlines clear criteria for selecting the alternative that causes the least overall harm: For projects where all of the reasonable alternatives involve some use of Section 4(f) property, the Final Rule lists factors that are to be balanced and weighed when making a decision as to which alternative will cause the least overall harm. These criteria are located in section 774.3(c). Once that alternative has been selected, all reasonable measures to minimize that harm or mitigate adverse impacts to the property in question must be included in the project before Section 4(f) approval can be granted.


Section 6009(c) of SAFETEA-LU requires that the U.S. Department of Transportation examine, evaluate, and report on the effectiveness of the new Section 4(f) provisions. In coordination with the Transportation Research Board, FHWA and FTA are currently undertaking an evaluation study, which includes an examination of:
  • Processes used to implement Section 6009(c), with an analysis of resulting efficiencies.
  • Post-construction effectiveness of impact mitigation and avoidance commitments adopted as part of projects.
  • Total number of projects determined to have de minimis impacts.
  1. Defines and implements the procedures for determining a de minimis impact: The procedures for determining de minimis impacts to 4(f) resources, which were outlined in the FHWA and FTA guidance document issued on December 13, 2005, are formally codified in regulation through the new Final Rule. The Final Rule ensures that current Section 4(f) regulations are consistent with the Section 4(f) statute, as amended by SAFETEA-LU. In addition to formally implementing the procedures for determining a de minimis impact, the Final Rule defines a de minimis impact as one that does not adversely affect the features, attributes, or activities qualifying the property for protection under Section 4(f). FHWA also plans to update its Section 4(f) Policy Paper to reflect SAFETEA-LU and the Final Rule once the latter takes effect. Requirements for de minimis impact determinations are located in section 774.3(b), 774.5(b), 774.7(b), and within the definitions in 774.17.

  2. Updates exceptions to Section 4(f) requirements: The Final Rule updates a number of existing exceptions to the Section 4(f) requirements, such as clarifying the applicability of the exception for restoration, rehabilitation, or maintenance of historical transportation facilities, and for the first time codifies several new exceptions that advance the regulation's preservation purpose. These include:
    • The Interstate System and some of its individual elements
    • Certain trails, paths, sidewalks, bikeways, and recreational facilities that are located within the transportation right of way
    • Transportation enhancement projects and mitigation activities where use of the Section 4(f) property is solely for the purpose of preserving or enhancing an activity, feature, or attribute that qualifies the property for Section 4(f) protection
    The seven 4(f) exceptions are located in section 774.13.

  3. Clarifies the option of applying a Programmatic Section 4(f) Evaluation: The Final Rule makes it clear that a Programmatic Evaluation merely establishes a simpler approach to compliance for certain classes of projects and does not in itself provide an exemption to Section 4(f) requirements. The new rule specifies the process for applying an existing Programmatic Evaluation as well as the process for developing a new one. Requirements for Programmatic Evaluations are located in section 774.3(d) and 774.5(c).

The Final Rule will take effect on April 11, 2008.

2 For more information on the Overton Park case, visit

Contact Information

Lamar Smith, CEP
Federal Highway Administration
Office of Project Development
and Environmental Review
1200 New Jersey Avenue, SE
Washington, DC 20590

Joseph Ossi
Federal Transit Administration
Office of Planning and
1200 New Jersey Avenue, SE
Washington, DC 20590

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