CCTV inspection view inside a metal corrugated culvert. At the connection between two pipe sections, the section closer to the camera is shifted sideways so its inner edge sticks out unevenly into the opening. This creates a visible step and narrow ledge along one side, with rough, broken concrete and exposed metal rods. The rest of the pipe is smooth, cylindrical, and dark further inside. Grainy CCTV camera footage. See more