Osterdock Rd over Carlan Creek
Clayton County, Iowa · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Osterdock Rd over Carlan Creek in Clayton County, Iowa, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1981, making it 44 years old at the 2025 inventory.
- It carries about 311 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 141 of the 257 inventoried bridges in Clayton County rated fair (54.9%); 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 November 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 → (42.73351, -91.15821)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Culvert | 5 | 5 | Fair condition |
Bridge details
| Structure | Concrete culvert |
| Length | about 26 ft |
| Location | 070000505 |
| NBI structure number | 000000000009110 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | November 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.