Glossary of Terms

Terms and acronyms that are commonly used in the Portal Bridge Capacity Enhancement Project website are provided below.

Design Life: Projected life (in years) of a new structure or structural component carrying the load (or weight) for which it was designed and under normal environmental conditions before replacement or major rehabilitation is expected.

Fixed Railroad Bridge: A railroad bridge characterized by permanent horizontal and vertical alignment.

Infrastructure: The underlying foundation or basic framework of a system.

Lead Federal Agency: The federal agency taking primary responsibility for preparing an environmental impact statement, as prescribed in 40CFR§1508.16.

Mean High Water (MHW): The average of high tide water heights observed over a period.

Mitigation: Planning of project design and/or construction to avoid or overcome adverse impacts.

Moveable Railroad Bridge: A railroad bridge where the horizontal or vertical alignment is such that it can be mechanically manipulated to permit the passage of traffic underneath.

National Environmental Policy Act (NEPA): Legislation enacted in 1969 that established a national environmental policy requiring that any project using federal funding or requiring federal approval (including transportation projects) must examine the effects that the proposal and alternative choices would have on the environment before a federal decision is made.

Northeast Corridor: The electrified railway line that runs from Washington, D.C. to Boston, Massachusetts, passing through Baltimore, Maryland; Wilmington, Delaware; Philadelphia, Pennsylvania; New York, New York; New Haven, Connecticut; and Providence, Rhode Island.

Preferred Alternative: The alternative selected from a comprehensive evaluation of all alternatives, which is the most acceptable resolution to the problems identified in the purpose and need.

Preliminary Engineering and Design: Phase of a project after the Environmental Impact Statement (EIS) process involving more detailed engineering analysis, environmental assessment and permit coordination, and initial design.

Project Sponsor: The agency proposing to build or implement a proposed project or action.

Record of Decision: A written public record issued by the lead federal agency once all the requirements of the environmental review process have been satisfied. It identifies the alternative chosen, mitigation and monitoring measures to be implemented, and other information relative to the decision. For the Portal Bridge Capacity Enhancement Project, the Record of Decision was issued by the Federal Railroad Administration in December 2008.

Swing Span Rail Bridge: A moveable bridge with a span that pivots (swings) open to allow traffic to pass through or underneath. The existing Portal Bridge is an example of a swing span rail bridge.