US 20 over Iowa River
Hardin County, Iowa · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US 20 over Iowa River in Hardin 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 2003, making it 22 years old at the 2025 inventory.
- It carries about 9,200 vehicles a day (traffic count year 2022).
- Its listed owner is the state highway agency.
- It is one of 87 of the 241 inventoried bridges in Hardin County rated good (36.1%); 69 (28.6%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its class is unchanged from 2024 (good), but component ratings moved: substructure 8 to 7.
- Its most recent inspection on record is dated August 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 → (42.43698, -93.07318)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 8 | 7 | Good condition |
Bridge details
| Structure | Continuous steel stringer or multi-beam girder |
| Length | about 1,639 ft |
| Location | 1.5 mi. W of Jct. SR S56 |
| NBI structure number | 000000000608350 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | August 2024 |
| 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 Hardin County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 20 over Drainage | 2003 | 9,800 | Good |
| US 20 over Drainage | 2003 | 9,200 | Good |
| US 65 over Iowa River | 2011 | 7,800 | Good |
| Washington St over Iowa River | 1934 | 6,251 | Fair |
| US 65 over Beaver Creek | 1976 | 5,300 | Good |
| US 20 EB over D 35 (elm St) | 2003 | 4,900 | Fair |
All bridges nearby: Hardin County, IA bridge conditions · every bridge in Hardin County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.