Ia 51 over Yellow River
Allamakee County, Iowa · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Ia 51 over Yellow River in Allamakee County, Iowa, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 1967, making it 58 years old at the 2025 inventory.
- It carries about 2,690 vehicles a day (traffic count year 2022).
- Its listed owner is the state highway agency.
- It is one of 62 of the 197 inventoried bridges in Allamakee County rated good (31.5%); 21 (10.7%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated August 2023, on a 24-month routine inspection cycle.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (43.14111, -91.57059)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Continuous steel stringer or multi-beam girder |
| Length | about 245 ft |
| Location | 4.0 Mi. N of Jct. 18 |
| NBI structure number | 000000000013580 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | August 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Iowa department of transportation.
Busiest bridges in Allamakee County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Ia 9 over Stream | 1967 | 3,670 | Fair |
| Ia 51 over Hecher Creek | 1967 | 2,690 | Good |
| Front St over Clear Creek | 1985 | 2,418 | Good |
| Ia 76 over Yellow River | 1980 | 2,370 | Fair |
| Ia 76 over Drainage Ditch | 1996 | 2,370 | Good |
| Ia 9 over Mississippi River | 1931 | 2,200 | Poor |
All bridges nearby: Allamakee County, IA bridge conditions · every bridge in Allamakee County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.