Twilight Drive over Iowa Ditch
Pennington County, South Dakota · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Twilight Drive over Iowa Ditch in Pennington County, South Dakota, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 8 (very good condition) on the 0-9 scale.
- It was built in 1998, making it 27 years old at the 2025 inventory.
- It carries about 389 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 121 of the 348 inventoried bridges in Pennington County rated good (34.8%); 21 (6.0%) are rated poor.
- 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 → (44.06741, -103.13637)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Culvert | 8 | Very good condition |
Bridge details
| Structure | Continuous concrete culvert |
| Length | about 24 ft |
| Location | 0.3W of Reservoir Rd |
| NBI structure number | 000000052457310 |
| Condition class | Good |
Source: FHWA National Bridge Inventory, 2025 data as reported by the South Dakota department of transportation.
Busiest bridges in Pennington County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I090 over Boxelder Ck | 1994 | 26,980 | Good |
| Cambell St over Ck | 1964 | 23,179 | Fair |
| SD079NF over St Joseph St Rcp&e RR | 1964 | 23,179 | Fair |
| Cambell St over Rapid Ck | 1967 | 21,415 | Fair |
| West Main St. over Rapid Ck | 1975 | 20,745 | Good |
| SD231 over Rapid Ck | 1974 | 20,057 | Fair |
All bridges nearby: Pennington County, SD bridge conditions · every bridge in Pennington County · South Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.