US Bridges

FM over Br Nishnabotna River

Fair

Audubon County, Iowa · 079352701 · Structure no. 000000000067690

Built
1963
62 years old
Condition
Fair
inspected June 2024
Type
Culvert
Concrete Continuous
Length
23 ft
2 main spans
Daily traffic
34
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Br Nishnabotna River is a concrete continuous culvert carrying FM over Br Nishnabotna River in Audubon County, Iowa. It was built in 1963, so it is 62 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 34 vehicles a day, projected to reach 34 by 2044. The structure is 23 ft (7 m) long. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesFM
CrossesBr Nishnabotna River
Location079352701
RouteCounty Highway 0
CountyAudubon County
StateIowa
Coordinates41.63061, -94.91619
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
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 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
Waterway adequacy4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating33.2 US tons
Inventory rating19.8 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadH 15
Structure length23 ft (7 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic34 (2022)
Projected traffic34 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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 FM over Br Nishnabotna River built?

It was built in 1963, making it 62 years old in 2025.

What condition is FM over Br 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 FM over Br Nishnabotna River carry?

About 34 vehicles per day (2022 count).

How long is FM over Br Nishnabotna River?

The structure is 23 ft (7 m) long with a longest span of 10 ft (3 m).

Who owns FM over Br Nishnabotna River?

It is owned by the County Highway Agency.