US Bridges

Osterdock RD over Carlan Creek

Fair

Clayton County, Iowa · 070000505 · Structure no. 000000000009110

Built
1981
44 years old
Condition
Fair
inspected November 2024
Type
Culvert
Concrete
Length
27 ft
2 main spans
Daily traffic
311
2022 count
Owner
County
County Highway Agency

About this bridge

Osterdock RD over Carlan Creek is a concrete culvert carrying Osterdock RD over Carlan Creek in Clayton County, Iowa. It was built in 1981, so it is 44 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 5 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 311 vehicles a day, roughly 18% of them trucks, projected to reach 311 by 2044. The structure is 27 ft (8.2 m) long. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesOsterdock RD
CrossesCarlan Creek
Location070000505
RouteCity Street 0
CountyClayton County
StateIowa
Coordinates42.73351, -91.15821
Functional classRural Major Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating34 US tons
Inventory rating25 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans2
Design loadH 20
Structure length27 ft (8.2 m)
Longest span12 ft (3.7 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic311 (2022)
Projected traffic311 by 2044
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 Osterdock RD over Carlan Creek built?

It was built in 1981, making it 44 years old in 2025.

What condition is Osterdock RD over Carlan Creek 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 2024.

How much traffic does Osterdock RD over Carlan Creek carry?

About 311 vehicles per day (2022 count), of which roughly 18% are trucks.

How long is Osterdock RD over Carlan Creek?

The structure is 27 ft (8.2 m) long with a longest span of 12 ft (3.7 m).

Who owns Osterdock RD over Carlan Creek?

It is owned by the County Highway Agency.