EB 20 & SB 17 over R-27
Hamilton County, Iowa · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- EB 20 & SB 17 over R-27 in Hamilton County, Iowa, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1978, making it 47 years old at the 2025 inventory.
- It carries about 5,500 vehicles a day (traffic count year 2022).
- 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.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- It was rated good in the 2024 inventory and is now fair (superstructure 7 to 6).
- Its most recent inspection on record is dated March 2024, on a 24-month routine inspection cycle.
- 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 → (42.449, -93.83571)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 6 | Satisfactory condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Prestressed concrete stringer or multi-beam girder |
| Length | about 142 ft |
| Location | 0.8 Mi W of E Jct Ia 17 |
| NBI structure number | 000000000603680 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | March 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | N: not over a waterway |
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.