NB US 61 over Silver Creek
Clinton County, Iowa · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- NB US 61 over Silver Creek in Clinton County, Iowa, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1974, making it 51 years old at the 2025 inventory.
- It carries about 6,350 vehicles a day (traffic count year 2022).
- Its listed owner is the state highway agency.
- It is one of 102 of the 375 inventoried bridges in Clinton County rated fair (27.2%); 12 (3.2%) 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 July 2023, 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 → (41.83884, -90.56873)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Prestressed concrete stringer or multi-beam girder |
| Length | about 208 ft |
| Location | 0.9 Mi. N of N Jct US 30 |
| NBI structure number | 000000000602840 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | July 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Iowa department of transportation.
Busiest bridges in Clinton County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 61 over Dd #15 | 1981 | 17,600 | Good |
| US 30 & 67 over Mill Creek | 2000 | 17,300 | Fair |
| US 30 & US 67 over over UPRR | 2000 | 17,200 | Good |
| US 67 over over UP RR | 1978 | 11,200 | Fair |
| US 30 over Mississippi Rvr RR S 2ND | 1956 | 11,100 | Fair |
| Ia 136 over Mississippi River & RR | 1974 | 11,000 | Fair |
All bridges nearby: Clinton County, IA bridge conditions · every bridge in Clinton County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.