US Bridges

FM over Nishnabotna River

FairPosted for load

Carroll County, Iowa · 082353303 · Structure no. 000000000093630

Built
1900
125 years old, rebuilt 1977
Condition
Fair
inspected March 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
52 ft
1 main span
Daily traffic
45
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Nishnabotna River is a steel stringer/multi-beam or girder carrying FM over Nishnabotna River in Carroll County, Iowa. It was built in 1900 and reconstructed in 1977, 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 fair condition with a lowest component rating of 6 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 45 vehicles a day, projected to reach 45 by 2044. The structure is 52 ft (15.9 m) long and 31 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesFM
CrossesNishnabotna River
Location082353303
RouteCounty Highway 0
CountyCarroll County
StateIowa
Coordinates41.87738, -94.91812
Functional classRural Minor 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2024
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 geometry7: Better than present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating35.8 US tons
Inventory rating20.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length52 ft (15.9 m)
Longest span50 ft (15.2 m)
Deck width31 ft (9.4 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic45 (2022)
Projected traffic45 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Nishnabotna River built?

It was built in 1900, making it 125 years old in 2025. It was reconstructed in 1977.

What condition is FM over Nishnabotna River 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 March 2024.

How much traffic does FM over Nishnabotna River carry?

About 45 vehicles per day (2022 count).

How long is FM over Nishnabotna River?

The structure is 52 ft (15.9 m) long with a longest span of 50 ft (15.2 m) and a deck 31 ft wide.

Who owns FM over Nishnabotna River?

It is owned by the County Highway Agency.