473rd Avenue over Big Sioux River
FairMoody County, South Dakota · 8.0W & 8.9N of Flandreau · Structure no. 000000051070011
- Built
- 1976
- 49 years old
- Condition
- Fair
- inspected July 2024
- Type
- Tee Beam
- Prestressed Concrete
- Length
- 150 ft
- 3 main spans
- Daily traffic
- 50
- 2022 count
- Owner
- County
- County Highway Agency
About this bridge
473rd Avenue over Big Sioux River is a prestressed concrete tee beam carrying 473rd Avenue over Big Sioux River in Moody County, South Dakota. It was built in 1976, so it is 49 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 50 vehicles a day, roughly 2% of them trucks, projected to reach 50 by 2032. The structure is 150 ft (45.7 m) long and 30 ft wide. If it were closed, the detour would be 3.7 mi (6 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
| 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. |
| Channel and channel protection | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was 473rd Avenue over Big Sioux River built?
It was built in 1976, making it 49 years old in 2025.
What condition is 473rd Avenue 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 July 2024.
How much traffic does 473rd Avenue over Big Sioux River carry?
About 50 vehicles per day (2022 count), of which roughly 2% are trucks.
How long is 473rd Avenue over Big Sioux River?
The structure is 150 ft (45.7 m) long with a longest span of 49 ft (14.9 m) and a deck 30 ft wide.
Who owns 473rd Avenue over Big Sioux River?
It is owned by the County Highway Agency.