US 18 over Drainage Ditch
Clay County, Iowa · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US 18 over Drainage Ditch in Clay County, Iowa, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1965 and reconstructed in 1994, making it 60 years old at the 2025 inventory.
- It carries about 4,270 vehicles a day (traffic count year 2022).
- Its listed owner is the state highway agency.
- It is one of 80 of the 154 inventoried bridges in Clay County rated fair (51.9%); 16 (10.4%) are rated poor.
- 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 → (43.12659, -94.97268)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Culvert | 6 | Satisfactory condition |
Bridge details
| Structure | Continuous concrete culvert |
| Length | about 28 ft |
| Location | At the jct of SR N14 |
| NBI structure number | 000000000020380 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Iowa department of transportation.
Busiest bridges in Clay County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 18 & 71 over Little Sioux River | 2006 | 16,900 | Good |
| US 71 over Br of Little Meadow Crk | 1990 | 11,400 | Fair |
| US 71 over Prairie Creek | 2017 | 4,770 | Good |
| US 18 over Lost Island Outlet | 1931 | 4,270 | Fair |
| US 18 over Little Sioux River | 2010 | 4,170 | Good |
| US 18 over Little Sioux Overflow | 1931 | 4,170 | Fair |
All bridges nearby: Clay County, IA bridge conditions · every bridge in Clay County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.