FM 310TH St over Dry Creek
Buchanan County, Iowa · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- FM 310TH St over Dry Creek in Buchanan County, Iowa, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1956, making it 69 years old at the 2025 inventory.
- It carries about 110 vehicles a day (traffic count year 2021).
- Its listed owner is the county highway agency.
- It is one of 161 of the 320 inventoried bridges in Buchanan County rated fair (50.3%); 20 (6.2%) 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 December 2024, on a 24-month routine inspection cycle.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (42.34025, -91.65294)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Prestressed concrete stringer or multi-beam girder |
| Length | about 87 ft |
| Location | 087072201 |
| NBI structure number | 000000000080860 |
| Condition class | Fair |
| Traffic status (item 41) | Posted for another load-capacity restriction (speed, number of vehicles on the bridge, etc.) |
| Last inspection (item 90) | December 2024 |
| Inspection interval (item 91) | 24 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 Buchanan County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-380 over Mud Creek | 1983 | 17,700 | Good |
| US 20 over Drainage Ditch | 1980 | 10,700 | Good |
| 1ST St W over Wapsipinicon River | 1917 | 10,258 | Fair |
| US 20 over Drainage Ditch | 1980 | 10,100 | Good |
| US 20 over Drainage Ditch | 1980 | 10,100 | Fair |
| Ia 150 over Wapsipinicon River | 1927 | 9,000 | Fair |
All bridges nearby: Buchanan County, IA bridge conditions · every bridge in Buchanan County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.