US Bridges

Ia 92 over West Nishnabotna River

Fair

Pottawattamie County, Iowa · 0.1 Mi. W of Carson · Structure no. 000000000043860

Built
1929
96 years old, rebuilt 1955
Condition
Fair
inspected June 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
355 ft
4 main spans
Daily traffic
2,320
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 92 over West Nishnabotna River is a steel continuous stringer/multi-beam or girder carrying Ia 92 over West Nishnabotna River in Pottawattamie County, Iowa. It was built in 1929 and reconstructed in 1955, so it is 96 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.

It carries about 2,320 vehicles a day, roughly 17% of them trucks, projected to reach 2,320 by 2044. The structure is 355 ft (108.2 m) long and 34 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesIa 92
CrossesWest Nishnabotna River
Location0.1 Mi. W of Carson
RouteState Highway 92
CountyPottawattamie County
StateIowa
Coordinates41.23288, -95.42662
Functional classRural Minor Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 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
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating34.3 US tons
Inventory rating20.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4 (+1 approach)
Design loadHS 20
Structure length355 ft (108.2 m)
Longest span81 ft (24.7 m)
Deck width34 ft (10.4 m)
Roadway width28 ft (8.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,320 (2022)
Projected traffic2,320 by 2044
Trucks17%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Ia 92 over West Nishnabotna River built?

It was built in 1929, making it 96 years old in 2025. It was reconstructed in 1955.

What condition is Ia 92 over West 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 June 2024.

How much traffic does Ia 92 over West Nishnabotna River carry?

About 2,320 vehicles per day (2022 count), of which roughly 17% are trucks.

How long is Ia 92 over West Nishnabotna River?

The structure is 355 ft (108.2 m) long with a longest span of 81 ft (24.7 m) and a deck 34 ft wide.

Who owns Ia 92 over West Nishnabotna River?

It is owned by the State Highway Agency.