Ia 21 over Deep River
Poweshiek County, Iowa · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Ia 21 over Deep River in Poweshiek County, Iowa, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 1962, making it 63 years old at the 2025 inventory.
- It carries about 1,730 vehicles a day (traffic count year 2022).
- Its listed owner is the state highway agency.
- It is one of 66 of the 243 inventoried bridges in Poweshiek County rated good (27.2%); 95 (39.1%) 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 June 2024, on a 24-month routine inspection cycle.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (41.59123, -92.35535)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Prestressed concrete stringer or multi-beam girder |
| Length | about 166 ft |
| Location | 1.0 Mi. N of Jct. Ia 85 |
| NBI structure number | 000000000045890 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | June 2024 |
| 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 Poweshiek County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-80 over N.fk. English River | 1963 | 28,500 | Fair |
| I-80 over No Fork English River | 1963 | 28,500 | Fair |
| EB I-80 over 50TH Street | 1963 | 14,250 | Fair |
| I 80 WB over UP RR | 2023 | 14,000 | Good |
| WB I-80 over 50TH Street | 1963 | 14,000 | Fair |
| EB I-80 over SR V18 | 1963 | 13,600 | Fair |
All bridges nearby: Poweshiek County, IA bridge conditions · every bridge in Poweshiek County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.