US018 over Cottonwood Ck
Tripp County, South Dakota · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US018 over Cottonwood Ck in Tripp County, South Dakota, 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 1965, making it 60 years old at the 2025 inventory.
- It carries about 1,746 vehicles a day (traffic count year 2024).
- Its listed owner is the state highway agency.
- It is one of 38 of the 89 inventoried bridges in Tripp County rated fair (42.7%); 22 (24.7%) 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 → (43.38643, -100.01762)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 6 | Satisfactory condition |
| Superstructure | 6 | Satisfactory condition |
| Substructure | 6 | Satisfactory condition |
Bridge details
| Structure | Continuous concrete slab |
| Length | about 66 ft |
| Location | 0.5 E Jct US 183N |
| NBI structure number | 000000062115270 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the South Dakota department of transportation.
Busiest bridges in Tripp County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US018 over Dog Ear Ck | 1965 | 3,553 | Fair |
| US018 Ser Rd over Ck | 1965 | 2,820 | Fair |
| US018 over Sand Ck | 1973 | 2,052 | Fair |
| US018 over Ck | 1973 | 1,803 | Fair |
| US018 over Big Hollow Ck | 1965 | 1,746 | Good |
| SD044 over Sand Ck | 1969 | 1,172 | Fair |
All bridges nearby: Tripp County, SD bridge conditions · every bridge in Tripp County · South Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.