US018 over Big Sioux River
FairLincoln County, South Dakota · At Iowa Border · Structure no. 000000042201136
- Built
- 1978
- 47 years old
- Condition
- Fair
- inspected March 2024
- Type
- Stringer/Multi-beam or Girder
- Steel Continuous
- Length
- 580 ft
- 4 main spans
- Daily traffic
- 2,130
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
US018 over Big Sioux River is a steel continuous stringer/multi-beam or girder carrying US018 over Big Sioux River in Lincoln County, South Dakota. It was built in 1978, so it is 47 years old, younger 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 2,130 vehicles a day, roughly 19% of them trucks, projected to reach 3,425 by 2043. The structure is 580 ft (176.8 m) long and 47 ft wide. If it were closed, the detour would be 24.2 mi (39 km).
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 | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was US018 over Big Sioux River built?
It was built in 1978, making it 47 years old in 2025.
What condition is US018 over Big Sioux River 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 March 2024.
How much traffic does US018 over Big Sioux River carry?
About 2,130 vehicles per day (2023 count), of which roughly 19% are trucks.
How long is US018 over Big Sioux River?
The structure is 580 ft (176.8 m) long with a longest span of 162 ft (49.4 m) and a deck 47 ft wide.
Who owns US018 over Big Sioux River?
It is owned by the State Highway Agency.