US 6 over Iais RR
Iowa County, Iowa · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US 6 over Iais RR in Iowa County, Iowa, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1956, making it 69 years old at the 2025 inventory.
- It carries about 1,000 vehicles a day (traffic count year 2022).
- Its listed owner is the state highway agency.
- It is one of 104 of the 239 inventoried bridges in Iowa County rated fair (43.5%); 45 (18.8%) 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 June 2024, on a 24-month routine inspection cycle.
- It has fracture-critical members (NBI item 92A): steel tension members without a redundant load path, which get their own scheduled inspections.
- 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 → (41.74212, -92.24603)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Continuous steel stringer or multi-beam girder |
| Length | about 331 ft |
| Location | 1.6 Mi. E of E Jct Ia 21 |
| NBI structure number | 000000000029320 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | June 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | N: not over a waterway |
| Fracture critical (item 92A) | Yes |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Iowa department of transportation.
Busiest bridges in Iowa County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-80 over Clear Creek | 1963 | 33,800 | Good |
| I 80 over Stream | 1963 | 33,000 | Fair |
| I-80 over No Name Creek | 1963 | 31,400 | Fair |
| I-80 over Stream | 1962 | 30,300 | Fair |
| I-80 over Old Mans Creek | 1962 | 30,100 | Fair |
| I-80 over Stream | 1961 | 29,700 | Good |
All bridges nearby: Iowa County, IA bridge conditions · every bridge in Iowa County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.