390TH St over Small Stream
Clayton County, Iowa · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 390TH St over Small Stream in Clayton County, Iowa, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 7 (good condition) on the 0-9 scale.
- It was built in 1958, making it 67 years old at the 2025 inventory.
- It carries about 79 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 78 of the 257 inventoried bridges in Clayton County rated good (30.4%); 38 (14.8%) 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 October 2024, 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 → (42.65878, -91.60137)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Culvert | 7 | 7 | Good condition |
Bridge details
| Structure | Concrete culvert |
| Length | about 30 ft |
| Location | 091063101 |
| NBI structure number | 000000000362980 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 2024 |
| 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 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.