310TH St over Miners Creek
Clayton County, Iowa · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 310TH St over Miners Creek in Clayton County, Iowa, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 4 (poor condition) on the 0-9 scale.
- It was built in 1915, making it 110 years old at the 2025 inventory.
- It carries about 4 vehicles a day (traffic count year 2022).
- Its listed owner is a city or municipal highway agency.
- It is one of 38 of the 257 inventoried bridges in Clayton County rated poor (14.8%); 38 (14.8%) are rated poor.
- Its traffic status in the 2025 inventory is posted for another load-capacity restriction (speed, number of vehicles on the bridge, etc.) (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated October 2023, on a 12-month routine inspection cycle.
- A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (42.77668, -91.11066)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 4 | 4 | Poor condition |
| Superstructure | 4 | 4 | Poor condition |
| Substructure | 4 | 4 | Poor condition |
Bridge details
| Structure | Concrete slab |
| Length | about 37 ft |
| Location | 000000000 |
| NBI structure number | 000000000005740 |
| Condition class | Poor |
| Traffic status (item 41) | Posted for another load-capacity restriction (speed, number of vehicles on the bridge, etc.) |
| Last inspection (item 90) | October 2023 |
| Inspection interval (item 91) | 12 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Iowa department of transportation.
Busiest bridges in Clayton County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 18 over Mississippi River Ia 76 | 1974 | 10,100 | Fair |
| Ia 13 over Roberts Creek | 1979 | 4,900 | Good |
| Bridge St over Turkey River | 1889 | 4,755 | Fair |
| US 18 over Unnamed Creek | 1988 | 4,730 | Fair |
| US 18 & 52 over Branch Roberts Creek | 1967 | 4,140 | Fair |
| US 18 over Bloody Run & Dme RR | 1988 | 4,140 | Fair |
All bridges nearby: Clayton County, IA bridge conditions · every bridge in Clayton County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.