Developing a better link between the transportation planning and environmental review processes for transportation projects has long been a goal of transportation agencies.

Despite the fact that highway and transit projects must flow from metropolitan and statewide transportation plans, studies performed and decisions reached as part of transportation planning traditionally have not been used in conducting environmental analyses under the National Environmental Policy Act (NEPA).

Environmental resource and permitting agencies often have had little involvement in the transportation planning process, becoming involved only after projects have been selected. As a result, planning decisions often were questioned and revisited in the NEPA process.

The Federal Highway Administration (FHWA) has been working for years to “change the culture” and address this “disconnect” between transportation planning and NEPA. In February 2005, FHWA and the Federal Transit Administration jointly issued a program guidance document, titled “Linking the Transportation Planning and NEPA Processes.” An updated version of the guidance was issued in February 2007 as Appendix A to the final regulations on statewide and metropolitan planning (23 CFR Part 450).

“When the NEPA and transportation planning processes are not well coordinated, the NEPA process may lead to the development of information that is more appropriately developed in the planning process, resulting in duplication of work and delays in transportation improvements,” the agencies stated in the final guidance.

Federal and state transportation agencies now are working to ensure that statewide and metropolitan transportation planning is the foundation for highway and transit project decisions.

FHWA considers planning and environment linkages as “an approach to transportation decision-making that considers environmental, community, and economic goals early in the planning stage and carries them through project development, design, and construction. This can lead to a seamless decision-making process that minimizes duplication of effort, promotes environmental stewardship, and reduces delays in project implementation,” FHWA states on its planning and environment linkages website.

Legislative Provisions

In August 2005, Congress enacted a comprehensive highway and transit reauthorization law, the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU). Section 6001 of SAFETEA-LU included major revisions to the existing statewide and transportation planning requirements in Sections 134 and 135 of Title 23 of the U.S. Code. One of the key elements of Section 6001 was an increased emphasis on early consideration of environmental issues in transportation planning.

Section 6001 included the following changes relating to consideration of environmental issues in the planning process:

    • Metropolitan and long-range transportation plans must be developed in consultation with state and local agencies responsible for land use management, natural resources, environmental protection, conservation, and historic preservation, as appropriate. The consultation must include a comparison of transportation plans with available state conservation plans or maps and inventories of natural or historic resources.
    • Metropolitan and long-range transportation plans must include a discussion of potential environmental mitigation activities, to be developed in consultation with federal, state, and tribal wildlife, land management, and regulatory agencies.
    • The planning factor related to environment was expanded to promote “consistency between transportation improvements and state and local planned growth and economic development patterns.”

Effective July 1, 2007, all metropolitan and statewide transportation plans, transportation improvement programs, and statewide transportation improvement programs were required to be consistent with all SAFETEA-LU planning provisions.

In addition to specific planning-related provisions, SAFETEA-LU Section 6002 (23 U.S.C. 139) provided a new environmental review process that emphasizes interagency collaboration and participation, supporting the concept of early consideration of environmental concerns in transportation planning.

Additional changes were made in the Moving Ahead for Progress in the 21st Century Act (MAP-21). Congress enacted a new authority for PEL in MAP-21 and amended it in 2015 through the Fixing America’s Surface Transportation Act (FAST Act). That authority, 23 U.S.C. 168 (Section 168), provides a process by which agencies may adopt or incorporate by reference a planning product to use during the environmental review process. For more information, link to the FHWA PEL Questions and Answers guidance.

FHWA Planning Rules and Guidance on NEPA-Planning Linkage (Appendix A to 23 CFR 450)

In response to SAFETEA-LU and other statutory and policy changes over the years, FHWA and FTA issued final regulations on statewide and metropolitan planning, on Feb. 14, 2007.

The planning regulations include two sections that directly address the planning-NEPA linkage in both statewide and metropolitan planning: 23 CFR 450.212 and 450.318. These new sections allow a “corridor or sub-area study” to be prepared as part of statewide or metropolitan planning. The regulations specifically allow a corridor or sub-area study to be used as the basis for carrying planning-level decisions and analyses forward into the NEPA process.

The planning regulations also include an “Appendix A,” which contains revised guidance on linking planning and NEPA. Appendix A supersedes the February 2005 program guidance on planning-NEPA linkage.

Appendix A describes environmental review for transportation projects as a “continuum of sequential study, refinement, and expansion” that begins in planning and continues through project development and NEPA.

The degree to which planning studies and decisions may be used in the NEPA process depends on how well the planning products met standards established by NEPA guidance and regulations, according to the guidance.

FHWA stressed the importance of new requirements for metropolitan planning organizations and states to consult with environmental, regulatory, and resource agencies in the planning process. Interagency cooperation and sharing of data on environmental resources early in the planning process can help agencies find a solution that meets the goals of the community, the environment, and transportation.

Appendix A provides the following list of questions to help practitioners analyze planning products for use in the NEPA process:

    • How much time has passed since the planning studies and corresponding decisions were made?
    • Were the future year policy assumptions used in the transportation planning process related to land use, economic development, transportation costs, and network expansion consistent with those to be used in the NEPA process?
    • Is the information still relevant/valid?
    • What changes have occurred in the area since the study was completed?
    • Is the information in a format that can be appended to an environmental document or reformatted to do so?
    • Are the analyses in a planning-level report or document based on data, analytical methods, and modeling techniques that are reliable, defensible, and consistent with those used in other regional transportation studies and project development activities?
    • Were the FHWA and FTA, other agencies, and the public involved in the relevant planning analysis and the corresponding planning decisions?
    • Were the planning products available to other agencies and the public during NEPA scoping?
    • During NEPA scoping, was a clear connection between the decisions made in planning and those to be made during the project development stage explained to the public and others? What was the response?
    • Are natural resource and land use plans being informed by transportation planning products, and vice versa?

Appendix A also provides advice regarding how transportation planning may be used to shape a project’s purpose and need, and conditions under which the NEPA process may be initiated in conjunction with transportation planning.

For more information, link to Appendix A contained in the final regulations on statewide and metropolitan planning. See also subsequent FHWA Guidance on Using Corridor and Subarea Planning to Inform NEPA (2011).

As mentioned, Congress enacted a new authority for PEL in MAP-21 and amended it in 2015 through the FAST Act., which provides a process by which agencies may adopt or incorporate by reference a planning product to use during the environmental review process. For more information, link to the FHWA PEL Questions and Answers guidance.


State and federal transportation agencies have many efforts underway to better integrate transportation planning and environmental considerations.

To encourage such efforts, FHWA has worked with state transportation agencies on linking planning and NEPA, and state-specific action plans have been developed to follow through on recommendations for integration. Examples of state action plans are available on FHWA’s Planning and Environment Linkages Effective Practices website.

Transportation agencies also are developing a range of tools to assist in integration of transportation planning and environmental considerations.

FHWA has developed an implementation tool, including a set of indicators designed to help agencies improve efforts at integration and identify available assistance.

Planning and Environment Linkages also is a key element of FHWA’s Every Day Counts Initiative as a tool to shorten project delivery. According to the agency, “Transportation agencies can conduct a ‘PEL study,’ which is any type of transportation planning study conducted at the corridor or subarea level, to link planning information directly or by reference into NEPA. To be viable in NEPA, a PEL study must involve interested State, local, Tribal, and Federal agencies as well as the public, document relevant decisions in a form that is identifiable and available for review during the NEPA scoping process and can be appended to or referenced in the NEPA document, and be accepted by the NEPA lead agencies.”

As part of its implementation tools, FHWA introduced the PEL Questionnaire, an adaptation of a questionnaire jointly developed by the Colorado Department of Transportation and FHWA Colorado Division Office to ensure that planning information and decisions are properly documented to be utilized in the NEPA review process. For more information, link to FHWA’s PEL/EDC Tools.


Closely related to PEL, Eco-Logical is an interagency approach to infrastructure development that organizes methods for addressing natural resource identification, avoidance, minimization and mitigation into a systematic, step-wise process that starts at the beginning of the transportation planning process and concludes with establishing programmatic approaches to recurring natural resource issues that are implemented at the project level.

FHWA and AASHTO have been actively involved in providing technical assistance and guidance to transportation agencies in implementing Eco-Logical, including a number of products and resources developed under the Second Strategic Highway Research (SHRP2) program. (See the Eco-Logical Library)

A wide range of resources and background materials on implementation are available on FHWA’s Implementing the Eco-Logical Approach website.