520TH Ave over Worrell Creek
Story County, Iowa · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 520TH Ave over Worrell Creek in Story 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 1966, making it 59 years old at the 2025 inventory.
- It carries about 2,324 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 160 of the 302 inventoried bridges in Story County rated fair (53.0%); 40 (13.2%) 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 → (41.99922, -93.65774)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Culvert | 6 | Satisfactory condition |
Bridge details
| Structure | Continuous concrete culvert |
| Length | about 26 ft |
| Location | 083241610 |
| NBI structure number | 000000000314880 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Iowa department of transportation.
Busiest bridges in Story County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-35 over Ballard Creek | 1964 | 48,300 | Fair |
| I-35 over Walnut Creek | 1964 | 48,300 | Fair |
| I 35 over South Skunk Rvr Overflow | 2017 | 48,300 | Good |
| I-35 over Drainage Ditch | 1967 | 28,300 | Good |
| US 69 over Ioway Creek | 1924 | 24,600 | Good |
| NB I-35 over Bike Path | 1964 | 24,150 | Fair |
All bridges nearby: Story County, IA bridge conditions · every bridge in Story County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.