Ia 21 over US 20
FairBlack Hawk County, Iowa · At Jct. US 20 · Structure no. 000000000605220
- Built
- 1983
- 42 years old
- Condition
- Fair
- inspected May 2023
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 267 ft
- 4 main spans
- Daily traffic
- 7,700
- 2022 count
- Owner
- State
- State Highway Agency
About this bridge
Ia 21 over US 20 is a prestressed concrete stringer/multi-beam or girder carrying Ia 21 over US 20 in Black Hawk County, Iowa. It was built in 1983, so it is 42 years old, younger 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 7,700 vehicles a day, roughly 4% of them trucks, projected to reach 7,700 by 2042. The structure is 267 ft (81.4 m) long and 87 ft wide. If it were closed, the detour would be 3.1 mi (5 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 | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Ia 21 over US 20 built?
It was built in 1983, making it 42 years old in 2025.
What condition is Ia 21 over US 20 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 May 2023.
How much traffic does Ia 21 over US 20 carry?
About 7,700 vehicles per day (2022 count), of which roughly 4% are trucks.
How long is Ia 21 over US 20?
The structure is 267 ft (81.4 m) long with a longest span of 92 ft (28 m) and a deck 87 ft wide.
Who owns Ia 21 over US 20?
It is owned by the State Highway Agency.