Which bridge type uses straight cables connected to a tower and is economical for long spans?

• A. Cable-Stayed Bridge
• B. Arch Bridge
• C. Truss Bridge
• D. Cantilever Bridge

Answer: (A)

The main idea is that long-span efficiency comes from a direct load path from the deck to the tower using straight cables. In a cable-stayed bridge, cables run in straight lines from the deck up to one or more towers, carrying tension directly into the towers and foundations. This simple, direct arrangement provides a stiff, stable structure with less material and simpler construction than other long-span options, making it economical for long spans.

Arch bridges rely on arches to carry loads in compression, which becomes impractical for very long spans due to the mass and thickness required. Truss bridges use many members to form a rigid lattice, which adds weight and complexity for long spans. Cantilever bridges need balanced overhangs and can demand substantial construction effort and materials. By contrast, the straight, tower-connected cables of a cable-stayed design give efficient load distribution and erection for long spans, which is why this type is favored for economical long-span solutions.