Which bridge is modular and can accommodate various uses and provide passage?

• A. Beam / Girder Bridge
• B. Cantilever Bridge
• C. Truss Bridge
• D. Movable Bridge

Answer: (D)

Movable bridges are designed to let the structure adapt to different needs by opening or rearranging its span to permit traffic on the waterway while still carrying road or rail traffic when closed. This capability makes them inherently versatile in use: they can serve vehicles and pedestrians when the waterway is quiet, and they can be opened to let ships and boats pass when a vessel is coming through. The modular aspect comes from the way the bridge deck or sections can be moved, lifted, swung, or rotated, using standardized components and mechanisms, so parts of the span can operate independently or be replaced/configured as needed.

Fixed types like beam/girder, cantilever, or truss bridges don’t include a mechanism to create an opening for waterway passage, so they’re designed for one mode of use unless substantial redesign is undertaken.