Ia 1 NB over Iowa River
PoorJohnson County, Iowa · 079061000 · Structure no. 000000000031720
- Built
- 1915
- 110 years old, rebuilt 1986
- Condition
- Poor
- inspected August 2023
- Type
- Arch - Deck
- Concrete Continuous
- Length
- 342 ft
- 3 main spans
- Daily traffic
- 10,950
- 2022 count
- Owner
- City
- City or Municipal Highway Agency
About this bridge
Ia 1 NB over Iowa River is a concrete continuous arch - deck carrying Ia 1 NB over Iowa River in Johnson County, Iowa. It was built in 1915 and reconstructed in 1986, so it is 110 years old, older than the Iowa average of 45.5 years.
The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
It carries about 10,950 vehicles a day, roughly 4% of them trucks, projected to reach 10,950 by 2043. The structure is 342 ft (104.2 m) long and 50 ft wide. If it were closed, the detour would be 8.1 mi (13 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Superstructure | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Substructure | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Ia 1 NB over Iowa River built?
It was built in 1915, making it 110 years old in 2025. It was reconstructed in 1986.
What condition is Ia 1 NB over Iowa River in?
The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in August 2023.
How much traffic does Ia 1 NB over Iowa River carry?
About 10,950 vehicles per day (2022 count), of which roughly 4% are trucks.
How long is Ia 1 NB over Iowa River?
The structure is 342 ft (104.2 m) long with a longest span of 114 ft (34.7 m) and a deck 50 ft wide.
Who owns Ia 1 NB over Iowa River?
It is owned by the City or Municipal Highway Agency.