330TH Street over I029
Union County, South Dakota · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 330TH Street over I029 in Union County, South Dakota, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1961, making it 64 years old at the 2025 inventory.
- It carries about 488 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 77 of the 169 inventoried bridges in Union County rated fair (45.6%); 41 (24.3%) are rated poor.
- 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 → (42.60514, -96.57603)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 6 | Satisfactory condition |
| Superstructure | 5 | Fair condition |
| Substructure | 5 | Fair condition |
Bridge details
| Structure | Continuous concrete multiple box beam |
| Length | about 365 ft |
| Location | Jefferson Interchange |
| NBI structure number | 000000064115330 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the South Dakota department of transportation.
Busiest bridges in Union County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I029 S over Big Sioux Rv | 1990 | 18,090 | Good |
| I029 N over Big Sioux Rv | 1963 | 18,090 | Fair |
| I029 over Ck | 1961 | 11,970 | Good |
| I029 over Ck | 1961 | 11,970 | Good |
| I029 over Ck | 1961 | 11,970 | Good |
| I029 S over River Drive | 1981 | 9,870 | Good |
All bridges nearby: Union County, SD bridge conditions · every bridge in Union County · South Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.