FM over Drainage Ditch
Hamilton County, Iowa · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- FM over Drainage Ditch in Hamilton County, Iowa, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 4 (poor condition) on the 0-9 scale.
- It was built in 1949, making it 76 years old at the 2025 inventory.
- It carries about 15 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 32 of the 165 inventoried bridges in Hamilton County rated poor (19.4%); 32 (19.4%) are rated poor.
- Its traffic status in the 2025 inventory is posted for load (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated September 2023, on a 24-month routine inspection cycle.
- A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (42.40446, -93.48234)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 4 | 4 | Poor condition |
| Superstructure | 4 | 4 | Poor condition |
| Substructure | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Continuous concrete slab |
| Length | about 69 ft |
| Location | 088232502 |
| NBI structure number | 000000000171650 |
| Condition class | Poor |
| Traffic status (item 41) | Posted for load |
| Last inspection (item 90) | September 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
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.