170th Street over Mt. Zion Branch
PoorAdams County, Iowa · 072331201 · Structure no. 000000000059720
- Built
- 1965
- 60 years old
- Condition
- Poor
- inspected January 2023
- Type
- Tee Beam
- Prestressed Concrete
- Length
- 31 ft
- 1 main span
- Daily traffic
- 20
- 2022 count
- Owner
- County
- County Highway Agency
About this bridge
170th Street over Mt. Zion Branch is a prestressed concrete tee beam carrying 170th Street over Mt. Zion Branch in Adams County, Iowa. It was built in 1965, so it is 60 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 20 vehicles a day, projected to reach 20 by 2043. The structure is 31 ft (9.4 m) long and 20 ft wide. If it were closed, the detour would be 1.9 mi (3 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 | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Channel and channel protection | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was 170th Street over Mt. Zion Branch built?
It was built in 1965, making it 60 years old in 2025.
What condition is 170th Street over Mt. Zion Branch 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 January 2023.
How much traffic does 170th Street over Mt. Zion Branch carry?
About 20 vehicles per day (2022 count).
How long is 170th Street over Mt. Zion Branch?
The structure is 31 ft (9.4 m) long with a longest span of 29 ft (8.8 m) and a deck 20 ft wide.
Who owns 170th Street over Mt. Zion Branch?
It is owned by the County Highway Agency.