I 29 SB over Big Sioux River
GoodWoodbury County, Iowa · South Dakota State Line · Structure no. 000000000053941
- Built
- 1990
- 35 years old
- Condition
- Good
- inspected April 2023
- Type
- Stringer/Multi-beam or Girder
- Steel Continuous
- Length
- 557 ft
- 3 main spans
- Daily traffic
- 15,600
- 2022 count
- Owner
- State
- State Highway Agency
About this bridge
I 29 SB over Big Sioux River is a steel continuous stringer/multi-beam or girder carrying I 29 SB over Big Sioux River in Woodbury County, Iowa. It was built in 1990, so it is 35 years old, younger than the Iowa average of 45.5 years.
The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 15,600 vehicles a day, roughly 18% of them trucks, projected to reach 15,600 by 2043. The structure is 557 ft (169.8 m) long and 43 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I 29 SB over Big Sioux River built?
It was built in 1990, making it 35 years old in 2025.
What condition is I 29 SB over Big Sioux River in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in April 2023.
How much traffic does I 29 SB over Big Sioux River carry?
About 15,600 vehicles per day (2022 count), of which roughly 18% are trucks.
How long is I 29 SB over Big Sioux River?
The structure is 557 ft (169.8 m) long with a longest span of 225 ft (68.6 m) and a deck 43 ft wide.
Who owns I 29 SB over Big Sioux River?
It is owned by the State Highway Agency.