Highway Projects:

Many Federal and State Environmental Review Requirements Are Similar, and Little Duplication of Effort Occurs

GAO-15-71: Published: Nov 18, 2014. Publicly Released: Nov 18, 2014.

Additional Materials:


David J. Wise
(202) 512-2834


Susan Sawtelle
(202) 512-6417


Office of Public Affairs
(202) 512-4800

What GAO Found

Three factors—project funding sources and project characteristics, and whether a state allows the adoption of federal review documents—generally determine whether a highway project needs a federal environmental review under the National Environmental Policy Act (NEPA) or a state environmental review under state law, or both. Projects without federal highway funding usually do not require a Federal Highway Administration (FHWA) NEPA review, but NEPA reviews of highway projects may still be required to obtain federal permits. Thresholds for environmental review vary under state environmental policy acts (SEPA) and may include project cost or length, whereas NEPA focuses on the potential for significant environmental impacts. Eighteen states have SEPAs required for highway projects, and 17 of these allow for the partial or full adoption of FHWA analyses or documentation to meet state environmental review requirements, according to GAO's survey of these states.

State environmental review requirements are generally similar to the FHWA NEPA process—including consideration of impacts, development and evaluation of project alternatives, mitigation of adverse project impacts, interagency coordination, and public involvement—although differences in specific requirements may affect key environmental decisions. For example, for the consideration of environmental impacts of a proposed highway project, a majority of states responding to GAO's survey indicated that their requirements are similar to FHWA's NEPA requirements overall. However, officials in 7 states GAO surveyed reported that their SEPA requirements related to social and environmental justice impacts are less stringent than FHWA's NEPA requirements. In addition, while state public involvement requirements are generally similar to FHWA's NEPA requirements overall, individual requirements vary, ranging from states that have no requirements to allow public involvement to others that may have more stringent requirements than FHWA's. Officials in 3 states told GAO that in practice they match FHWA's NEPA public involvement requirements for state-only reviews to meet public expectations, even if state law requires less. Further, in the absence of required federal NEPA reviews, certain federal laws related to protection of parklands and historic preservation may not apply to a project, potentially affecting whether a project is determined to have significant impacts and whether those impacts are mitigated.

Officials in 4 of the 18 states in GAO's survey identified instances of potential federal–state duplication in environmental review processes, stemming either from supplemental state requirements or from the lack of alignment between required federal and state review documents. By contrast, 10 of the states in GAO's survey reported that there was no duplication in environmental reviews. Generally, state officials explained that little duplication of effort occurs in state and federal review processes because these reviews are done concurrently by state officials able to address requirements with analyses used for different purposes without replicating effort. Further, 7 of the 10 states reporting no duplication allow for the adoption of a NEPA review to fulfill SEPA requirements. Finally, 4 states pointed to potential duplication or overlap that did not stem from the interaction of state and federal requirements, such as the rework necessary to keep environmental reviews up to date.

Why GAO Did This Study

Under NEPA, federal agencies evaluate the potential environmental impacts of proposed projects. FHWA has developed a process for NEPA reviews for federal-aid highway projects, such as roads or bridges. According to the Council on Environmental Quality (CEQ) and GAO analysis, 18 states have SEPAs that also require the review of environmental impacts of a variety of actions for highway projects.

The Moving Ahead for Progress in the 21st Century Act (MAP-21) required GAO to examine state environmental reviews for highway projects, including whether they duplicate federal environmental reviews for federal-aid highway projects. This report focuses solely on environmental reviews of highway projects in states with SEPAs and addresses 1) factors determining whether federal or state environmental reviews are required; 2) how state and federal review requirements compare; and 3) the extent of any duplication in federal and state reviews, including frequency and cost. GAO reviewed FHWA and CEQ documents and interviewed officials of these federal agencies; analyzed state laws and regulations; surveyed the 18 states with SEPAs required for highway projects; and interviewed selected state agencies within 9 of those states based on the number of FHWA NEPA reviews underway and other factors.

This report has no recommendations. The U.S. Department of Transportation and CEQ provided technical corrections about federal and state environmental review requirements, which GAO incorporated as appropriate.

For more information, contact David J.Wise at (202) 512-2834 or wised@gao.gov or wised@gao.gov or Susan Sawtelle at (202) 512-6417 or sawtelles@gao.gov.

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