A deck is the surface of a bridge. A structural element of its superstructure, it may be constructed of concrete, steel, open grating, or wood. Sometimes the deck is covered by a railroad bed and track, asphalt concrete, or other form of pavement for ease of vehicle crossing. A concrete deck may be an integral part of the bridge structure (T-beam or double tee structure) or it may be supported with I-beams or steel girders.
When a bridge deck is installed in a through truss, it is sometimes called a floor system.[1] A suspended bridge deck will be suspended from the main structural elements on a suspension or arch bridge. On some bridges, such as a tied-arch or a cable-stayed, the deck is a primary structural element, carrying tension or compression to support the span.
A deck bridge is one in which the deck itself is the main structural element, itself carrying the roadway. Contrast to a truss bridge which may carry a deck on the top chords or bottom chords of a structural truss.