2026 Complete In-Service Bridge Safety Inspection Practice Test

Understanding culvert types and how they carry load with or without a floor helps here. A frame culvert is built from concrete frames that form the sides and top, but it does not have a continuous bottom floor across the span. The road or fill material sits on top of these frames, while water flows through the openings of the frame. This arrangement matches the description of being constructed of concrete, having no floor, and being covered with fill material.

Cast-in-place concrete describes a method of constructing concrete, often including a floor, rather than a floorless frame system. A rigid culvert refers to a solid-bottom, continuous-shell type, not a floorless frame structure. A culvert in general is any opening for water under a roadway, but the specific floorless, frame-based design is what defines frame culverts.