CO B-20 over I-35
FairCerro Gordo County, Iowa · 3.9 Mi. N of Jct. US 18 · Structure no. 000000000019250
- Built
- 1970
- 55 years old
- Condition
- Fair
- inspected April 2024
- Type
- Stringer/Multi-beam or Girder
- Steel Continuous
- Length
- 298 ft
- 4 main spans
- Daily traffic
- 2,318
- 2022 count
- Owner
- State
- State Highway Agency
About this bridge
CO B-20 over I-35 is a steel continuous stringer/multi-beam or girder carrying CO B-20 over I-35 in Cerro Gordo 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 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 2,318 vehicles a day, roughly 12% of them trucks, projected to reach 2,318 by 2044. The structure is 298 ft (90.8 m) long and 35 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 | 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was CO B-20 over I-35 built?
It was built in 1970, making it 55 years old in 2025.
What condition is CO B-20 over I-35 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 April 2024.
How much traffic does CO B-20 over I-35 carry?
About 2,318 vehicles per day (2022 count), of which roughly 12% are trucks.
How long is CO B-20 over I-35?
The structure is 298 ft (90.8 m) long with a longest span of 96 ft (29.3 m) and a deck 35 ft wide.
Who owns CO B-20 over I-35?
It is owned by the State Highway Agency.