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Successes in Stewardship
Monthly Newsletter
May 2003

Questions and Answers: FHWA's Interim Guidance
on Indirect and Cumulative Impacts

Considering Indirect and Cumulative Impacts in the NEPA Process

State departments of transportation (DOTs) and the Federal Highway Administration (FHWA) analyze the direct, indirect, and cumulative impacts of their actions as part of the National Environmental Policy Act (NEPA) process. While FHWA and state DOTs are making progress in incorporating indirect and cumulative impact considerations into project decisionmaking, the complexity of these issues can pose challenges. To help state DOTs analyze indirect and cumulative impacts and streamline the NEPA process, FHWA released its "Interim Guidance: Questions and Answers Regarding Indirect and Cumulative Impact Considerations in the NEPA Process" in January 2003.

Purpose of the Interim Guidance

The interim guidance is FHWA's initial step in addressing current indirect and cumulative impacts policy, guidance, and training needs. FHWA's interim guidance focuses attention on the existing NEPA requirements specific to indirect and cumulative impacts. FHWA believes that thoroughly reviewing the reasonably foreseeable direct and indirect impacts of transportation actions and appropriately documenting other cumulative impacts on specific resources are essential to making informed project decisions and attaining FHWA's environmental streamlining and stewardship goals. In addition to developing the interim guidance, FHWA is now planning other related activities, such as the development of supplemental policy and guidance, the possible revision of the FHWA's 1992 "Position Paper: Secondary and Cumulative Impact Assessment in the Highway Project Development Process," the development of training, and the collection and dissemination of examples and best practices.

overhead view of the Pierce Bridge along U.S. Route 302 in New Hampshire spanning a river with treelined banks
State DOTs and FHWA Divisions work on a variety of transportation projects, such as the Pierce Bridge along U.S. Route 302 in New Hampshire. FHWA's new interim guidance on indirect and cumulative impacts can assist them with addressing the indirect and cumulative impacts of projects.
(FHWA image)

To download "Interim Guidance: Questions and Answers
Regarding Indirect and Cumulative Impact Considerations in the NEPA Process,"
visit: http://www.fhwa.dot.gov/environment/guidebook/qaimpact.asp


  • Direct impacts are caused by an action and occur at the same time and place as the action.
  • Indirect impacts (also referred to as secondary impacts) are caused by the action and are later in time or farther removed in distance, but still reasonably foreseeable. Indirect impacts may include growth-inducing effects and other effects related to induced changes in the pattern of land use, population density or growth rate, and related effects on air, water, and other natural systems, including ecosystems.
  • Cumulative impacts are the impacts on the environment that result from the incremental impacts of the action when added to other past, present, and reasonably foreseeable future actions, regardless of what agency or person undertakes such other actions. Cumulative impacts can result from individually minor but collectively significant actions taking place over a period of time.

Definitions are based on CEQ regulations 40 CFR § 1500 - 1508.

Regulatory History of Indirect and Cumulative Impacts

Under NEPA, project sponsors are required to identify and avoid, minimize, or compensate for direct project impacts. While the NEPA legislation does not mention indirect or cumulative impacts, the Council on Environmental Quality (CEQ) established Federal agency responsibility for identifying, analyzing, and documenting direct, indirect, and cumulative impacts in its "Regulations for Implementing the Procedural Provisions of the National Environmental Policy Act (40 CFR §§ 1500 - 1508)." CEQ regulations direct that the environmental consequences section of an Environmental Impact Statement or Environmental Assessment include a discussion of adverse impacts that cannot be avoided, including direct and indirect impacts.

Other statutory and regulatory mandates include indirect and/or cumulative impact requirements, including the Endangered Species Act, Section 404 of the Clean Water Act, Section 106 of the National Historic Preservation Act, and Executive Order 12898 on Environmental Justice.

Highlights from the Interim Guidance

The interim guidance provides FHWA field offices, state DOTs, and other environmental practitioners with a variety of information, including:

  • Explanations of what direct, indirect, and cumulative impacts are and in what statutes, regulations, guidance, and court law they are found.
  • A review of existing NEPA requirements regarding consideration, analysis, documentation, and mitigation of direct, indirect, and cumulative impacts in Environmental Impact Statements, Environmental Assessments, and Categorical Exclusions.
  • Strategies for addressing indirect and cumulative impacts and for streamlining the project development process. Strategies discussed include early participation of all partners and stakeholders in project scoping, inventory of features, resources, ecosystems, and human communities within the project area of influence, and incorporation of planning considerations in the local area, such as land uses and transportation plans, into the project study.
  • Examples of several state DOTs' procedures for analyzing and documenting indirect and cumulative impacts.
  • References to indirect and cumulative impact guidance.
  • Training opportunities.

FHWA/EPA Workshops on Methods for Evaluating Secondary and Cumulative Land Use Impacts.

In February 2003, FHWA Headquarters and the New England Region (Region 1) of the U.S. Environmental Protection Agency co-sponsored one-day workshops on successful methods for evaluating the secondary and cumulative land use impacts of transportation projects. Workshops were held in Albany, New York, Hartford, Connecticut, and Boston, Massachusetts, and participants included representatives from state and Federal transportation and natural resource agencies, metropolitan planning organizations, non-profit organizations, local governments, universities, and private consulting firms. Participants reviewed the available methods for analyzing land use impacts of transportation projects, the guidelines for selecting methods, and a case study on the use of the Delphi Process, which utilizes expert panels. Methods discussed included comprehensive plans, qualitative techniques (including the Delphi Process), quantitative techniques, Geographic Information Systems (GIS) techniques, statistical methods, regional economic/demographic models, and land use models. More workshops may be held in the future due to their initial popularity.

Contact Information

Lamar Smith
FHWA Office of Project Development & Environmental Review
400 7th Street, SW
Room 3222
Washington, DC 20590
Phone: (202) 366-8994
Fax: (202) 366-7660
Email: Lamar.Smith@fhwa.dot.gov

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"Successes in Stewardship" is a Federal Highway Administration newsletter highlighting current environmental streamlining practices from around the country. To subscribe, contact Cassandra Allwell at (617) 494-3997 or allwell@volpe.dot.gov.

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