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Section 4(f) for Project Managers

park with walker on a walking trail

1. Introduction 

Section 4(f)Includes publicly owned parks, recreation areas and wildlife or waterfowl refuges, or any publicly or privately owned historical sites listed or eligible for listing on the National Register of Historic Places. of the U.S. Department of Transportation Act of 1966 — typically referred to as Section 4(f) — contains regulations governing the use of publicly owned public parks, recreation areas, wildlife and waterfowl refuges, as well as significant historic sites, on federally funded transportation projects. Publicly owned lands are those which are owned by government agencies or public institutions. Typically, Section 4(f) only applies to properties open to the public. Exceptions to this rule include nature and wildlife refuges as well as historic sites. These areas qualify for protection even if they are not publicly accessible. Section 4(f) approval may also be needed if KYTC needs to obtain FHWA approval for an action (e.g., change in access to the Interstate system).

Section 4(f) imposes a substantive requirement. This means Section 4(f) property can be used on a federally funded project if:

  • No prudent and feasible alternative exists which avoids use of the property
  • Project planning minimizes harm to the property

This article walks Project Managers (PMs) through the basics of Section 4(f). To streamline project development and delivery, PMs and project teams should work closely with Division of Environmental Analysis (DEA) subject matter-experts (SMEs) as they negotiate the Section 4(f) process.

2. Getting the Section 4(f) Process Started 

PMs must submit a project footprint to DEA SMEs so they can locate Section 4(f) properties located within it.

Equally important, during early stages of project development the PM must draft and refine a clear purpose and need statement. The purpose and need statement is an important tool for evaluating project alternatives and their direct impacts on Section 4(f) properties. First, it helps the Project Development Team(PDT) assess whether an avoidance alternative (i.e., an alternative that does not use a Section 4(f) property) is prudent. Second, if use of a Section 4(f) property is unavoidable, the purpose and need statement informs the selection of an alternative which causes the least overall harm.

KYTC must choose the alternative that causes the least overall harm to a Section 4(f) property. FHWA only approves projects that use Section 4(f) properties if:

  • No feasible and prudent avoidance alternative exists and KYTC minimizes impacts to the properties, or 
  • The use — including measures to minimize harm — has a de minimis impact (see Section 4 on how Section 4(f) defines use).

3. Properties Covered Under Section 4(f) 

Table 1 specifies the conditions under which Section 4(f) protects different property types. When the evaluation process begins, it is important to differentiate between historic properties and archaeological sites and other kinds of property, such as parks, recreation areas, and refuges.

Decisions about whether a historic property or archaeological site qualifies for protection under Section 4(f) are made as part of the Section 106 process. KYTC must evaluate properties that are at least 50 years old to make this determination. The HKP article on Section 106 provides an overview of this process — Section 4 of that article explicitly addresses Section 4(f).

Table 1. Properties Covered Under Section 4(f)
Property Type Conditions(s) for Section 4(f) Protection
Parks and Recreation Areas
  • Publicly owned
    • Includes properties owned by government agencies or public institutions
  • Open to the public
    • Does not apply to wildlife or waterfowl refuges
  • Major purpose of the property is to accommodate recreational activities or serve as a refuge
  • Official with jurisdiction (OWJ) has deemed the property significant for meeting park or recreation objectives
    • Judgements about significance must take under advisement the significance of an entire property — not just the portion being used or impacted
Historic and Cultural Sites
  • Listed or eligible for listing on the National Register of Historical Places (NRHP)
  • Has local historical significance, even if the property is not listed on or eligible for the NRHP
    • FHWA makes the final decision about whether Section 4(f) applies if a claim of local significance is made
  • Property does not have to be publicly owned or open to the public
Properties Managed for Multiple Uses
  • Areas designated in management plans as being significant for parks, recreation, or wildlife and waterfowl refuge purposes.
    • Examples include national forests, state parks, US Army Corps of Engineers properties, school grounds, military sites
Archaeological Sites
  • Listed or eligible for listing on the NRHP
    • Materials must warrant preservation in place. If they do not need to preserved in place, they are exempted from Section 4(f).

Use of the following property types does not require approval under Section 4(f):

  •  Maintenance, preservation, rehabilitation, operation, modernization, reconstruction, or replacement of historic transportation facilities if the Section 106 process concludes in a no adverse effect finding and the State Historic Preservation Officer (SHPO) does not object
  • Archaeological sites that are important for data recovery but which do not need to be preserved in place
  • Trails funded by the Recreational Trails Program
  • National Historic Trails designated as such under the National Trails System Act
  • Trails, paths, bikeways, or sidewalks located in a transportation facility’s right of way (ROW) and which can be maintained in the ROW
  • Trails, paths, bikeways, or sidewalks that are part of the local transportation system which serve primarily a transportation function
  • Transportation enhancement activities, alternative projects, and mitigation activities whose use preserves/ enhances property features that are used to designate the property as a Section 4(f) property
    • OWJ must provide a written concurrence
  • Temporary occupancy (see Section 4)
  • Interstate Highway System, except for features that FHWA deems as having national or exceptional historic significance
  • Formally reserved or jointly developed or planned property

4. What Does it Mean to Use a Section 4(f) Property?

Table 2 lists and defines the three types of uses recognized under Section 4(f).

Table 2. Use Types Defined by Section 4(f)
Use Case Definition
Permanent Incorporation
  • A Section 4(f) is permanently acquired and permanently incorporated into a transportation facility.
Temporary Occupancy
  • Temporary land occupancy (e.g., construction staging or access areas, detours, temporary bridges) as part of a construction project
    • Some forms of temporary land occupancy are not treated as a use under Section 4(f) (see below).
    • Temporary occupancy is considered a use if a property will suffer temporary or permanent adverse changes./ul>
Constructive Use
  • Occurs where nearby project impacts (e.g., noise, visual obstructions, loss of access, atmospheric effects) substantially impair a Section 4(f) property’s protected features, activities, or attributes.
    • Only occurs in the absence of Section 4(f) properties being permanently incorporated into a transportation facility

Sometimes temporary occupancy of a Section 4(f) does not count as a use. For this to be the case, the occupancy must meet all of the following criteria:

  • Use is temporary (shorter than the construction period) and no change in property ownership occurs
  • Scope of work is minor and changes to the property are minimal
  • Use will not result in permanent, adverse physical impacts. The project will not temporarily or permanently interfere with the property’s protected activities, features, or attributes.
  • Property must be restored to a condition that is equal to or better than its condition before the project.
  • Establishment of written agreements with the appropriate federal, state, or local OWJs

Failing to meet any of these criteria results in the temporary occupancy being classified as a use.

5. Section 4(f) Workflow

Once DEA identifies Section 4(f) properties within the project footprint, SMEs determine if the project will use these properties. To facilitate this evaluation, PMs need to submit preliminary engineering information to the DEA SME, including ROW boundaries and the locations of permanent or temporary easements. This should be done as early as possible during project planning and development. If DEA identifies potential uses of Section 4(f) properties, the PM and PDT should identify methods to avoid or minimize their use.

If a feasible and prudent alternative exists that avoids the use of Section 4(f) properties, KYTC must select it. Under Section 4(f) an alternative is not feasible if the PDT concludes — based on sound engineering judgment — that it cannot be built. An alternative is not prudent if it:

  • Fails to address the project needs
  • Produces unacceptable safety or operational problems
  • Compromises a project such that it is unreasonable to proceed with it given the stated purpose and need
  • Produces severe social, economic, or environmental impacts, severely disrupts established communities, results in severe disproportionate impacts to minority or low-income populations, or imposes severe impacts on environmental resources protected under other federal laws
  • Requires additional construction, maintenance, or operational costs of an extraordinary magnitude
  • Results in minor factors, which taken cumulatively, produce unique problems or impacts of an extraordinary magnitude

 5.1 de Minimis Impacts

If a Section 4(f) property will be used on a project, FHWA must determine if the use will culminate in a de minimis impact (i.e., a minor impact). A de minimis impact does not adversely affect the features, attributes, and activities that distinguish Section 4(f) properties as such. Critically, when a project is evaluated, separate de minimis impact determinations must be made for each Section 4(f) property. In other words, a single determination is not made for an entire project or alternative. When FHWA makes a de minimis impact determination, it factors into its decision avoidance, minimization, mitigation, enhancement measures that KYTC intends to implement. As such, the agency considers net impacts to the property.

Table 3 lists the criteria used to make de minimis impact determinations for historic sites as well as parks, recreation areas, and refuges. A de minimis impact determination can be made only if all criteria are satisfied.

Table 3. Requirements for a de minimis Impact Determination
Property Type Criteria
Historic Sites
  • Section 106 process returns a finding of no adverse effect or no historic properties affected.
  • FHWA informs OWJs that it intends to make a de minimis impact determination based on the OWJs’ written concurrence with the Section 106 determination.
  • FHWA has notified the public of its intention to make a de minimis impact determination and given the public adequate time to review and comment on the plans.
Parks, Recreation Areas, and Wildlife and Waterfowl Refuges
  • The use of Section 4(f) properties — combined with measures taken to avoid, minimize, or mitigate impacts as well as enhancements — do not adversely affect the activities and features that qualify them for Section 4(f) protections.
  • FHWA has notified and given members of the public the opportunity to review and comment on proposed impacts.
  • OWJs provide a written concurrence stating their agreement with the de minimis finding and confirm it will not adversely impact the activities and features that qualify Section 4(f) properties for protection.

It is important not to view a de minimis impact as a form of avoidance. Nor does an de minimis impact finding exempt a property from Section 4(f) requirements. A de minimis impact finding that authorizes a minor use of Section 4(f) can be made without needing to determine there are no feasible and prudent avoidance alternatives. An alternative with de minimis impacts cannot be treated as an avoidance alternative.

5.2 Programmatic Evaluations

KYTC has recourse to programmatic evaluations to address minor impacts to a range of Section 4(f) properties. They streamline the Section 4(f) process and are used in lieu of an individual evaluation (see Section 5.3). FHWA developed programmatic evaluations for projects types whose impacts at the project level tend to be broadly similar. Before using a programmatic evaluation, KYTC must demonstrate (a) there is no feasible and prudent avoidance alternative and (b) that it has completed all necessary planning to minimize harm to Section 4(f) properties. KYTC can use these evaluations as long as:

  • Project characteristics match the programmatic Section 4(f) evaluation
  • Project impacts are within the range specified in the programmatic Section 4(f) evaluation
  • All avoidance alternatives in the programmatic Section 4(f) evaluation have been assessed
  • OWJs have submitted a written agreement
  • All measures to minimize harm have been evaluated

Table 4 lists the major characteristics of each programmatic evaluation. It is a condensed version of a table available on FHWA’s Section 4(f) Tutorial.

Table 4. Characteristics of FHWA Section 4(f) Programmatic Evaluations
Independent Bikeway or Walkway Projects Use of Historic Bridges Minor Involvement with Parks, Recreation Lands, and Wildlife and Waterfowl Refuges Minor Involvement with Historic Sites Transportation Projects that Have a Net Benefit to a Section 4(f) Property
Project Type Independent bikeway or walkway projects that are not incidental to activities associated with a highway project Rehabilitation or replacement of historic bridges Improvement of the operational characteristics, safety and/or physical condition of an existing highway on essentially the same alignment Any project on an existing or new alignment
Resources Covered Parks or recreation areas Historic bridges not designated as a National Historic Landmark Parks, recreation lands, and wildlife and waterfowl refuges adjacent to the existing highway facility Historic sites adjacent to the existing highway facility All Section 4(f) properties
Impact Threshold No significant impacts. None of the following:
  • Displacements
  • Historic site impacts
  • Minimal water quality impacts
  • Section 4(f) does not apply if a bridge can be rehabilitated without impacting its historic integrity. Section 4(f) applies If the bridge will be demolished and/or replaced Amount of property that can be acquired/used from a Section 4(f) site:
    • If the total size is < 10 acres, up to 10% of the site.
    • If the total size is 10 – 100 acres, up to 1 acre.
    • If the total size is > 100 acres, up to 1% of the size.
    Amount of property that can be acquired/used from a Section 4(f) site:
    • If the total size is < 10 acres, up to 10% of the site.
    • If the total size is 10 – 100 acres, up to 1 acre.
    • If the total size is > 100 acres, up to 1% of the size.
    No impact limits. Projects must result in an overall enhancement of the property. For all properties, must receive concurrence from OWJs. For historic sites, the project should not alter the features that qualify the property for inclusion on the NRHP. Alterations could result in an adverse effect determination as long as the property stays eligible for the NRHP and the SHPO/THPO concurs there is a net benefit.
    Coordination and Concurrence Requirements OWJs concur in writing that the project is acceptable and consistent with the property’s designated use. Replacement bridges must be made available for an alternative use. SHPO concurs with the impact assessment and proposed mitigation. OWJs concur in writing with the impact assessment and proposed mitigation. SHPO/THPO concur in writing with the impact assessment and proposed mitigation OWJs or SHPO/THPO concur in writing with the impact assessment, proposed mitigation, proposed measures to minimize harm, mitigation measures, and that the Section 4(f) property will see a net benefit.
    Public Notice NEPA comment period NEPA and Section 106 comment period NEPA comment period NEPA and Section 106 comment period On projects with at least one public meeting, proposed use of the Section 4(f) properties will be communicated to the public.

    * Refers to the type of NEPA environmental document the programmatic agreement can be used with. CE = Categorical Exclusion, EA = Environmental Assessment, EIS = Environmental Impact Statement

    The programmatic evaluation KYTC uses most often is the one focused on the use of historic bridges. The availability of de minimis impact determinations has resulted in the agency rarely using other programmatic evaluations.

    5.3 Individual Section 4(f) Evaluation

    If use of Section 4(f) properties cannot be avoided, the use does not qualify as de minimis, the use is not a temporary occupancy, or the use does not fall under a programmatic evaluation, KYTC must prepare an individual Section 4(f) evaluation. As part of this process, the project team must assess a range of reasonable avoidance alternatives. If the PDT identifies avoidance alternatives but determines they are neither feasible nor prudent, the team must document how it reached this conclusion. Both quantitative and qualitative metrics should be used when comparing alternatives.

    When choosing between alternatives whose use of a Section 4(f) property exceeds the de minimis threshold, FHWA requires KYTC to select the one that produces the least overall harm. One way to minimize harm is to mitigate for adverse impacts (i.e., compensatory mitigation; unlike Section 404 of the Clean Water Act, Section 4(f), when applied to natural resources such as parks, does not require specific mitigation ratios). When evaluating alternatives, FHWA requires that KYTC base its assessment on the systematic comparison of seven factors (Table 5).

    Table 5. Evaluation Criteria for Comparing Impacts to Section 4(f) Properties
    Category Factors
    Net Harms to Section 4(f) Properties
    • Ability to mitigate adverse impacts to each Section 4(f) property.
    • After accounting for mitigation, the relative severity of harm inflicted on characteristics that qualify a Section 4(f) property for protection.
    • Relative significance of each Section 4(f) property.
    • OWJs’ views of each Section 4(f) property and whether they prefer one alternative over another.
    Issues Unrelated to Section 4(f)
    • How well each alternative meets the project’s purpose and need. If alternatives vary in the degree to which they meet the purpose and need, this should be documented.
    • After accounting for mitigation, the magnitude of adverse impacts to resources not protected by Section 4(f).
    • Differences in cost. A significant difference in cost between alternatives can be used to support the determination that one alternative results in the least overall harm.

    FHWA has identified several measures that can be used to minimize harm. These include making minor shifts in or adjustments to the project alignment, reducing the design speed, building retaining walls, narrowing typical sections, and doing construction in the offseason (to avoid impacting recreation activities).

    KYTC’s Environmental Analysis Guidance Manual includes a format that individual evaluations should follow. FHWA performs a legal sufficiency review for all individual Section 4(f) evaluations to verify that Section 4(f) requirements are met.

    6. Mitigation

    Adopting mitigation measures is one strategy to reduce the impacts or minimize harm to Section 4(f) properties. To determine what forms of mitigation are most appropriate, KYTC should consult with the OWJs. Mitigation to historic sites is typically adjudicated through the Section 106 process. The HKP article on Section 106 discusses mitigation strategies the Cabinet has used to address impacts to cultural, historic, and archaeological sites. With respect to mitigating impacts to public parks, recreation areas, wildlife and waterfowl refuges, and other features, a number of options are available. Mitigation should be proportional to the impact. FHWA cites several options:

    • Replace land/facilities where there is a Section 4(f) use with land/facilities that have a comparable value and function.
    • Monetary compensation to enhance land that remains around a Section 4(f) property. Payment of fair market value for the land.
    • Replace features and facilities impacted by the project (e.g., sidewalks, paths, benches, lights, trees, buildings).
    • Incorporate design or habitat features into the project.
    • Install vegetative buffers and screen off the project area.
    • Develop educational or interpretive documentation.

    7. Conclusion

    In a nutshell, the Section 4(f) process can be summed up as follows:

    • Identify Section 4(f) properties
    • Characterize how Section 4(f) properties are used
    • Evaluate avoidance alternatives to determine if they are feasible and prudent
    • Minimize impacts to Section 4(f) properties
    • Identify and implement mitigation measure commensurate with the impacts to Section 4(f) properties

    A best practice is to avoid Section 4(f) properties altogether. But for some projects this is not possible. If a project must use Section 4(f) properties, the PM and PDT — in consultation with DEA SMEs — should try to identify an alternative that only has minor impacts (i.e., de minimis impact determination). If more extensive use of a Section 4(f) property merits an individual evaluation, KYTC must choose the alternative that result in the least overall harm. Minimization and mitigation measures can be used to reduce the scope and scale of impacts. Communicating with the OWJs throughout the Section 4(f) process reduces disruptions and ensures that all stakeholders are on the same page.

    8. Resources

    AASHTO Practitioner’s Handbook (Complying with Section 4(f) of the U.S. DOT Act) — Contains a detailed review of Section 4(f), including questions that should guide each stage of the Section 4(f) process.

    Department of the Interior Handbook on Departmental Review of Section 4(f) Evaluation — Provides a thorough but relatively brief overview of the Section 4(f) process.

    FHWA Environmental Toolkit Section 4(f) Tutorial — Offers a good summary of Section 4(f) that illustrates the FHWA’s approach to interpretation and enforcement of Section 4(f) provisions.

    KYTC Environmental Analysis Guidance Manual — Includes a brief chapter on Section 4(f) and methods KYTC uses to maintain compliance.

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