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Environmental Review Toolkit

Interim Guidance on the Application of Travel and Land Use Forecasting in NEPA

Frequently Asked Questions

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Interim Guidance: April 6, 2010
FAQ: February 21, 2018
Reviewer Instructions: February 21, 2018

  1. What is the motivation and purpose of the Interim Guidance?
    Travel and land use forecasting is critical to project development and National Environmental Policy Act (NEPA) processes. Forecasts provide important information to project managers and decision-makers, and provide foundations for:
    • Determining purpose and need,
    • Evaluating the performance of alternatives, and
    • Estimating environmental impacts such as noise, emissions, induced land development, and indirect and/or cumulative effects.
    Forecasting methodologies and their applications may be a source of disagreement among agencies and interest groups, and have been the focus of project-level litigation.

    The purpose of this guidance is to encourage improvement in the state-of-the-practice in relation to how project-level forecasting is applied in the context of the NEPA process. While technical guidelines for producing forecasts for projects have been documented by others, little has been published on the procedural or process considerations in forecasting (how to apply forecasting in the context of NEPA). This guidance attempts to fill that gap.
  2. Who is the intended audience for the Interim Guidance?
    The primary audiences for the Interim Guidance are NEPA project managers, FHWA staff, forecasting groups at Metropolitan Planning Organizations (MPOs) and State Departments of Transportation (DOTs), as well as consultants that support MPOs and DOTs in conducting corridor and NEPA studies.
  3. Who is the intended audience for the Instructions for Reviewing Travel and Land Use Forecasting Analysis in NEPA Documents (Reviewer Instructions)?
    The Reviewer Instructions were developed for FHWA staff responsible for reviewing NEPA documents. Relevant FHWA staff include Community Planners, Environmental Specialists, and Office of Chief Counsel Attorneys. In addition, the instructions are intended to assist project sponsors and technical teams who are preparing NEPA documents, as the considerations raised here are often crucial to a successful project, and they are most easily addressed when they are identified early and carried out consistently during the NEPA process.
  4. Is following the Interim Guidance or the Reviewer Instructions mandatory?
    No. Following the Interim Guidance or the Reviewer Instructions is strictly voluntary. The guidance and instructions are based on lessons learned and best practices and do not constitute the establishment of an FHWA standard. Not all studies are the same; therefore this guidance is intended to be non-prescriptive, and its application flexible and scalable to the type and complexity of the travel analysis to be undertaken.
  5. Was there previous guidance on this topic and is it superseded by this guidance?
    No. This guidance is the first to be released from FHWA on this topic, and therefore does not supersede any previous guidance.
  6. Is the guidance only for large scale projects or projects that require an environmental impact statement?
    No. However certain sections of the document are more applicable to large projects, particularly when addressing large scale effects and impacts, such as changes in land development patterns. The guidance attempts to specify when sections are more appropriate for larger, more complex projects.
  7. What are the Reviewer Instructions and how are they related to the Interim Guidance?
    The purpose of the Reviewer Instructions is to support review of travel and land use forecasting elements of documents prepared pursuant to the National Environmental Policy Act (NEPA).  These instructions may be viewed as “advice” or “technical assistance.”
  8. To what extent do the Reviewer Instructions apply to NEPA Assignment States’ reviews and approvals of NEPA documents?
    NEPA Assignment states have assumed FHWA’s project-level NEPA and environmental review responsibilities. Assignment states are encouraged to consider the Interim Guidance and the Reviewer Instructions in their approach to traffic and land use forecasting.
  9. Who should I contact if I have questions about the Interim Guidance or the Reviewer Instructions?
    Questions regarding the Interim Guidance on the Application of Travel and Land Use Forecasting in NEPA and on the associated Instructions for Reviewing Travel and Land Use Forecasting Analysis in NEPA Documents may be directed to Brian Gardner (, 202-366-4061).