The NEPA sets national policy on protecting and enhancing the environment and acts as an umbrella under which other environmental laws, regulations, and policies are satisfied.

The EIS is an environmental document that presents the need for a project, reasonable design alternatives, environmental consequences, and it suggests environmental protection measures that can be taken to mitigate adverse impacts.

It is national policy that special effort should be made to preserve the natural beauty of the countryside and public park and recreation lands, wildlife and waterfowl refuges, and historic sites. In the USDOT Act of 1966, a special provision was included to provide protection to these resources. It is known as Section 4(f), and it stipulates that the FHWA will not approve any program or project which requires the use of any publicly owned public park, recreation area, or wildlife or waterfowl refuge, or any land from an historic site of national, state, or local significance unless there is no feasible and prudent alternative to the use, and all possible planning to minimize harm resulting from such use is incuded.

Executive Order 12898, Federal Actions to Address Environmental Justice in Minority and Low-Income Populations, seeks to avoid disproportionately high and adverse impacts on minority and low-income populations with respect to the environment.