US 20 Ramps Ag over Ramp over Ia 376 & UP RR
Woodbury County, Iowa · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US 20 Ramps Ag over Ramp over Ia 376 & UP RR in Woodbury 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 1976, making it 49 years old at the 2025 inventory.
- It carries about 12,500 vehicles a day (traffic count year 2022).
- Its listed owner is the state highway agency.
- It is one of 182 of the 455 inventoried bridges in Woodbury County rated fair (40.0%); 95 (20.9%) 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 August 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 → (42.44757, -96.37157)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Continuous steel stringer or multi-beam girder |
| Length | about 522 ft |
| Location | At jct. IA 376 |
| NBI structure number | 000000000600764 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | August 2023 |
| 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 Woodbury County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I29 NB Off Ramp over Perry Creek Conduit | 2017 | 91,000 | Good |
| US 77 over Missouri River & Rd | 1981 | 34,600 | Fair |
| I 29 Ia 12 over Drainage-all of Roadway | 1957 | 32,900 | Fair |
| US 77 over I 29 & Ia 12 NB | 2012 | 26,900 | Good |
| I 29 SB over Pierce St Frontage Rd | 2018 | 21,100 | Fair |
| Ia 12 over BNSF Rvr Sts & Ia 376 | 1936 | 20,600 | Poor |
All bridges nearby: Woodbury County, IA bridge conditions · every bridge in Woodbury County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.