SB I-35 over 310th Street
FairDecatur County, Iowa · 2.5 Mi. S of US 69 · Structure no. 000000000022840
- Built
- 1970
- 55 years old
- Condition
- Fair
- inspected July 2023
- Type
- Stringer/Multi-beam or Girder
- Steel Continuous
- Length
- 141 ft
- 3 main spans
- Daily traffic
- 7,250
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
SB I-35 over 310th Street is a steel continuous stringer/multi-beam or girder carrying SB I-35 over 310th Street in Decatur County, Iowa. It was built in 1970, so it is 55 years old, older than the Iowa average of 45.5 years.
The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 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 7,250 vehicles a day, roughly 39% of them trucks, projected to reach 7,250 by 2043. The structure is 141 ft (43 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
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 | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was SB I-35 over 310th Street built?
It was built in 1970, making it 55 years old in 2025.
What condition is SB I-35 over 310th Street 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 SB I-35 over 310th Street carry?
About 7,250 vehicles per day (2023 count), of which roughly 39% are trucks.
How long is SB I-35 over 310th Street?
The structure is 141 ft (43 m) long with a longest span of 52 ft (15.9 m) and a deck 43 ft wide.
Who owns SB I-35 over 310th Street?
It is owned by the State Highway Agency.