Duncan RD over I090
FairPennington County, South Dakota · 6.0 E New Und Interchange · Structure no. 000000052670285
- Built
- 1961
- 64 years old
- Condition
- Fair
- inspected July 2023
- Type
- Slab
- Concrete Continuous
- Length
- 254 ft
- 4 main spans
- Daily traffic
- 83
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
Duncan RD over I090 is a concrete continuous slab carrying Duncan RD over I090 in Pennington County, South Dakota. It was built in 1961, so it is 64 years old, older than the South Dakota average of 48.9 years.
The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
It carries about 83 vehicles a day, roughly 2% of them trucks, projected to reach 106 by 2043. The structure is 254 ft (77.4 m) long and 34 ft wide.
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Duncan RD over I090 built?
It was built in 1961, making it 64 years old in 2025.
What condition is Duncan RD over I090 in?
The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in July 2023.
How much traffic does Duncan RD over I090 carry?
About 83 vehicles per day (2023 count), of which roughly 2% are trucks.
How long is Duncan RD over I090?
The structure is 254 ft (77.4 m) long with a longest span of 65 ft (19.8 m) and a deck 34 ft wide.
Who owns Duncan RD over I090?
It is owned by the State Highway Agency.