US Bridges

560th Ave over Hamilton-Story 1 Open Dd

PoorPosted for load

Story County, Iowa · 085233102 · Structure no. 000000000316230

Built
1900
125 years old, rebuilt 1982
Condition
Poor
inspected December 2022
Type
Stringer/Multi-beam or Girder
Steel
Length
47 ft
1 main span
Daily traffic
34
2022 count
Owner
County
County Highway Agency

About this bridge

560th Ave over Hamilton-Story 1 Open Dd is a steel stringer/multi-beam or girder carrying 560th Ave over Hamilton-Story 1 Open Dd in Story County, Iowa. It was built in 1900 and reconstructed in 1982, so it is 125 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. Its operating status is: posted for load restriction.

It carries about 34 vehicles a day, projected to reach 34 by 2043. The structure is 47 ft (14.3 m) long and 25 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Carries560th Ave
CrossesHamilton-Story 1 Open Dd
Location085233102
RouteCounty Highway 0
StateIowa
Coordinates42.12405, -93.58157
Functional classRural Local

Condition and inspection

Poor

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.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionDecember 2022
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment7: Better than present minimum criteria
Operating rating38.5 US tons
Inventory rating23.1 US tons

Structure

MaterialSteel
DeckWood or timber
Main spans1 (+1 approach)
Design loadUnknown
Structure length47 ft (14.3 m)
Longest span31 ft (9.4 m)
Deck width25 ft (7.5 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic34 (2022)
Projected traffic34 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 560th Ave over Hamilton-Story 1 Open Dd built?

It was built in 1900, making it 125 years old in 2025. It was reconstructed in 1982.

What condition is 560th Ave over Hamilton-Story 1 Open Dd 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 December 2022.

How much traffic does 560th Ave over Hamilton-Story 1 Open Dd carry?

About 34 vehicles per day (2022 count).

How long is 560th Ave over Hamilton-Story 1 Open Dd?

The structure is 47 ft (14.3 m) long with a longest span of 31 ft (9.4 m) and a deck 25 ft wide.

Who owns 560th Ave over Hamilton-Story 1 Open Dd?

It is owned by the County Highway Agency.