170TH Street over Stream
Adams County, Iowa · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 170TH Street over Stream in Adams 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 1964, making it 61 years old at the 2025 inventory.
- It carries about 20 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 77 of the 185 inventoried bridges in Adams County rated fair (41.6%); 85 (45.9%) 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 January 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 → (41.0577, -94.59346)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Concrete channel beam |
| Length | about 25 ft |
| Location | 072331201 |
| NBI structure number | 000000000059710 |
| Condition class | Fair |
| Traffic status (item 41) | Posted for load |
| Last inspection (item 90) | January 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 Adams County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Ia 148 over East Nodaway River | 1976 | 3,580 | Fair |
| Ia 148 over over BNSF RR | 1976 | 3,580 | Good |
| US 34 over E Nodaway River & BNSF R | 1964 | 2,970 | Fair |
| US 34 over Metz Creek | 1921 | 2,390 | Fair |
| US 34 over Platte River | 2014 | 2,390 | Good |
| US 34 over Kemp Creek | 1964 | 2,240 | Fair |
All bridges nearby: Adams County, IA bridge conditions · every bridge in Adams County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.