Which term describes a hydraulic structure used to convey water under a road or railway and is typically under fill?

• A. Culvert
• B. Bridge
• C. Abutment
• D. Pier

Answer: (A)

This question is about structures that pass water beneath a road or railway. A culvert is the hydraulic structure designed to convey streams or stormwater under a roadway or railway, and it is typically placed under fill as the road sits above it. Culverts come in various shapes—pipes, box culverts, or arches—and their primary job is to maintain flow while allowing the crossing to carry traffic.

This differs from a bridge, which spans over water or other obstacles and carries traffic above the water; an abutment is the end support of a bridge, and a pier is a vertical support in the water for a bridge. Those terms describe parts of a bridge, not conduits for conveying water under traffic.