Structure 17540 · Cass County, IA
Carries US 71 over Four Mile Creek, 2.1 Mi. N Of N Jct. 92.
A culvert 22 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 | Cass |
| Location | 2.1 Mi. N Of N Jct. 92 |
| Carries | US 71 |
| Crosses | Four Mile Creek |
| Coordinates | 41.29009, -94.98440 |
| Material | Concrete Continuous |
| Design | Culvert |
| Total Length | 22.0 ft (6.7 m) |
| Max Span | 9.8 ft (3 m) |
| Deck Area | 89.8 sq m |
| Main Spans | 2 |
| Year Built | 1971 |
| Avg Daily Traffic | 2,280 (2022) |
| Truck Traffic | 18% |
| Lanes On Bridge | 2 |
| Last Inspection | September 2023 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Scour Critical | 8 — Stable, low risk |
| Structure Number | 000000000017540 |
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.