Which deck layout involves two parallel levels of deck separated by an intermediate floor?

• A. Corrugated Steel Deck
• B. Undivided Carriageway
• C. Double-Decked Bridges
• D. Timber Deck

Answer: (C)

The concept being tested is stacking bridge decks to create two traffic levels within the same bridge superstructure. A layout with two parallel levels of deck, one above the other, separated by an intermediate floor, is a double-decked bridge. This arrangement allows two separate decks to carry traffic independently while sharing the same supporting structure, effectively increasing capacity without widening the footprint. The intermediate floor between the decks provides the necessary separation and space for structural elements that transfer loads between the upper and lower decks, as well as any utilities or diaphragms needed for stability. The other options refer to a single deck type (corrugated steel deck), a single carriageway layout (undivided carriageway), or a different material choice (timber deck), none of which describe two stacked levels.