NB I-35 over Co Rd D-25
Hamilton County, Iowa · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- NB I-35 over Co Rd D-25 in Hamilton County, Iowa, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1974, making it 51 years old at the 2025 inventory.
- It carries about 8,250 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 72 of the 165 inventoried bridges in Hamilton County rated fair (43.6%); 32 (19.4%) 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 → (42.47088, -93.56862)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 5 | Fair condition |
| Superstructure | 5 | Fair condition |
| Substructure | 6 | Satisfactory condition |
Bridge details
| Structure | Continuous concrete slab |
| Length | about 143 ft |
| Location | at Junction With SR D25 |
| NBI structure number | 000000000602530 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Iowa department of transportation.
Busiest bridges in Hamilton County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I 35 over Drainage Ditch | 1966 | 27,200 | Fair |
| I 35 over Stream | 1965 | 26,900 | Good |
| I-35 over Tuttle Creek | 1967 | 17,400 | Fair |
| I-35 over Drainage Ditch 23 & 31 | 1972 | 16,600 | Good |
| I 35 NB over Ia 175 | 1966 | 11,850 | Fair |
| I 35 SB over Ia 175 | 1966 | 11,850 | Fair |
All bridges nearby: Hamilton County, IA bridge conditions · every bridge in Hamilton County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.