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New York State Thruway Authority

Glossary

Cantilevered Walkway: The section of bridge which carries the existing bridge railing and lighting. The walkway is not directly attached to the existing travel lanes but is cantilevered out from the travel lanes by means of a steel connection.

Causeway: A raised roadway over a body of water. On the Tappan Zee the section of bridge from Nyack to the west truss is a causeway.

Deck: The roadway of a bridge or causeway.

DMS: Dynamic Message Signs. Located on the roadway, these electronic signs are used to convey information about detours and delays.

EIS: Environmental Impact Statement.  An assessment of environmental impacts of alternatives to address a defined purpose and need.

Fascia Structural Steel: The steel girder which is located on the outermost point of the deck. The outermost girder under Lane 1 northbound and Lane 7 southbound is considered the fascia girder.

FHWA: Federal Highway Administration, under the United States Department of Transportation.

HAR: Highway Advisory Radio, 530 AM (Tappan Zee Corridor) and 1610 AM (Newburgh area). Provides up to date reports on traffic conditions throughout the Thruway system, including the Tappan Zee Bridge.

MNR: Metro-North Railroad (A subsidiary of the Metropolitan Transportation Authority)

MTA: Metropolitan Transportation Authority

NYSDOT: New York State Department of Transportation

NYSTA: New York State Thruway Authority

Service life: Projected life (in years) of an existing structure or structural component under normal loading and environmental conditions before replacement or major rehabilitation is required.

Substructure: The supporting part of a bridge; the foundation.

Superstructure: The part of the bridge above the substructure.

Truss: A rigid framework, usually of wood or metal, designed to support a structure. The Tappan Zee Bridge has an underdeck truss located between the causeway sections and the main span of the bridge. The main span consists of a cantilevered truss, which is visible when driving over the high point of the bridge.

TZB: Tappan Zee Bridge.