320TH Ave over Stream
Clay County, Iowa · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 320TH Ave over Stream in Clay County, Iowa, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 2007, making it 18 years old at the 2025 inventory.
- It carries about 21 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 58 of the 154 inventoried bridges in Clay County rated good (37.7%); 16 (10.4%) are rated poor.
- 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 → (43.23085, -94.9568)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 7 | Good condition |
| Superstructure | 7 | Good condition |
| Substructure | 7 | Good condition |
Bridge details
| Structure | Concrete slab |
| Length | about 23 ft |
| Location | 097351102 |
| NBI structure number | 000000000117231 |
| Condition class | Good |
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 Drainage Ditch | 1965 | 4,270 | Fair |
| US 18 over Little Sioux River | 2010 | 4,170 | Good |
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.