The bridge axis that follows a straight line, and the bridges should be constructed in straight to avoid extra forces.

• A. Curved Bridges
• B. Skewed Bridges
• C. Highway Bridge
• D. Straight Bridges

Answer: (D)

Bridge alignment determines how the loads travel through the structure and what kinds of internal forces are generated. When the axis is straight, the load path from the deck to the supports runs cleanly in plane, so the primary forces are vertical reactions and in‑plane bending moments. This keeps torsion and secondary moments to a minimum and makes the distribution of forces more predictable and simpler to manage in design and construction.

Curved alignments introduce curvature into the load path, which creates torsional effects and additional bending moments as the deck tends to carry loads along a curved route. The reactions at the piers and bearings become more complex, and the structure must resist twisting and lateral components that aren’t present in a straight alignment.

Skewed alignments (where the deck meets supports at an angle) also generate torsion and uneven load distribution, requiring more intricate detailing in bearings, diaphragms, and girder connections to handle the off-axis forces.

A highway bridge describes the function, not the geometry, so it doesn’t address the alignment-related behavior that’s being asked about.

Therefore, a straight bridge alignment minimizes these extra forces and simplifies the overall force path, making it the best choice.