US Bridges

FM over Nishnabotna Trib

PoorPosted for load

Montgomery County, Iowa · 071383103 · Structure no. 000000000254770

Built
1957
68 years old
Condition
Poor
inspected May 2023
Type
Slab
Concrete Continuous
Length
103 ft
3 main spans
Daily traffic
173
2021 count
Owner
County
County Highway Agency

About this bridge

FM over Nishnabotna Trib is a concrete continuous slab carrying FM over Nishnabotna Trib in Montgomery County, Iowa. It was built in 1957, so it is 68 years old, older than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.

It carries about 173 vehicles a day, projected to reach 173 by 2043. The structure is 103 ft (31.4 m) long and 27 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

Location

Open in Google Maps
CarriesFM
CrossesNishnabotna Trib
Location071383103
RouteCounty Highway 0
CountyMontgomery County
StateIowa
Coordinates40.91575, -95.25578
Functional classRural Major Collector

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating38.6 US tons
Inventory rating23.1 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 15
Structure length103 ft (31.4 m)
Longest span39 ft (11.9 m)
Deck width27 ft (8.2 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic173 (2021)
Projected traffic173 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 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 Nishnabotna Trib built?

It was built in 1957, making it 68 years old in 2025.

What condition is FM over Nishnabotna Trib in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in May 2023.

How much traffic does FM over Nishnabotna Trib carry?

About 173 vehicles per day (2021 count).

How long is FM over Nishnabotna Trib?

The structure is 103 ft (31.4 m) long with a longest span of 39 ft (11.9 m) and a deck 27 ft wide.

Who owns FM over Nishnabotna Trib?

It is owned by the County Highway Agency.