Walnut St over Monkey Run
Louisa County, Iowa · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Walnut St over Monkey Run in Louisa 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 1935, making it 90 years old at the 2025 inventory.
- It carries about 1,140 vehicles a day (traffic count year 2022).
- Its listed owner is a city or municipal highway agency.
- It is one of 81 of the 151 inventoried bridges in Louisa County rated fair (53.6%); 22 (14.6%) 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 → (41.28012, -91.36444)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Culvert | 5 | Fair condition |
Bridge details
| Structure | Concrete deck arch |
| Length | about 49 ft |
| Location | 075041901 |
| NBI structure number | 000000000002470 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Iowa department of transportation.
Busiest bridges in Louisa County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 61 over Millrace Creek | 1985 | 4,950 | Fair |
| US 61 over Overflow Iowa River | 1985 | 4,950 | Fair |
| US 61 over Overflow Iowa River | 1985 | 4,950 | Fair |
| US 61 over Overflow Iowa River | 1985 | 4,950 | Fair |
| US 61 over Muskrat Lake | 1985 | 4,950 | Fair |
| US 61 over Iowa River | 1980 | 4,950 | Fair |
All bridges nearby: Louisa County, IA bridge conditions · every bridge in Louisa County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.