Structure 237581 · Mahaska County, IA
Carries FM over Black Oak Creek, 076171002.
A culvert 21 ft across with 2 openings. Lengths are drawn to scale; at this length a semi-truck would be a speck. Each part is colored by its latest inspection rating. The inventory records lengths but not heights, so those are drawn as typical for a culvert.
| State | Iowa |
| County | Mahaska |
| Location | 076171002 |
| Carries | FM |
| Crosses | Black Oak Creek |
| Coordinates | 41.40124, -92.81445 |
| Material | Concrete Continuous |
| Design | Culvert |
| Total Length | 21.0 ft (6.4 m) |
| Max Span | 9.8 ft (3 m) |
| Deck Area | 54.4 sq m |
| Main Spans | 2 |
| Year Built | 2003 |
| Avg Daily Traffic | 170 (2022) |
| Lanes On Bridge | 2 |
| Last Inspection | December 2021 |
| Inspection Frequency | Every 48 months |
| Owner | County Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Scour Critical | 8 — Stable, low risk |
| Structure Number | 000000000237581 |
Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."
A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.