US Bridges

530th Ave over Keigley Branch

FairPosted for load

Story County, Iowa · 085242202 · Structure no. 000000000316400

Built
1917
108 years old
Condition
Fair
inspected November 2022
Type
Stringer/Multi-beam or Girder
Steel
Length
26 ft
1 main span
Daily traffic
20
2022 count
Owner
County
County Highway Agency

About this bridge

530th Ave over Keigley Branch is a steel stringer/multi-beam or girder carrying 530th Ave over Keigley Branch in Story County, Iowa. It was built in 1917, so it is 108 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. Its operating status is: posted for load restriction.

It carries about 20 vehicles a day, projected to reach 20 by 2043. The structure is 26 ft (7.9 m) long and 18 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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Carries530th Ave
CrossesKeigley Branch
Location085242202
RouteCounty Highway 0
CountyStory County
StateIowa
Coordinates42.16283, -93.64
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2022
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating34 US tons
Inventory rating20.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length26 ft (7.9 m)
Longest span23 ft (7 m)
Deck width18 ft (5.5 m)
Roadway width17 ft (5.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20 (2022)
Projected traffic20 by 2043
Trucks0%
Lanes on structure1
Traffic directionOne-lane bridge for two-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 statusPossibly eligible for the National Register; requires further investigation
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 530th Ave over Keigley Branch built?

It was built in 1917, making it 108 years old in 2025.

What condition is 530th Ave over Keigley Branch 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 November 2022.

How much traffic does 530th Ave over Keigley Branch carry?

About 20 vehicles per day (2022 count).

How long is 530th Ave over Keigley Branch?

The structure is 26 ft (7.9 m) long with a longest span of 23 ft (7 m) and a deck 18 ft wide.

Who owns 530th Ave over Keigley Branch?

It is owned by the County Highway Agency.