US Bridges

FM over Nishnabotna Trib

PoorPosted for load

Montgomery County, Iowa · 072380303 · Structure no. 000000000255500

Built
1949
76 years old
Condition
Poor
inspected May 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
33 ft
1 main span
Daily traffic
29
2021 count
Owner
County
County Highway Agency

About this bridge

FM over Nishnabotna Trib is a steel stringer/multi-beam or girder carrying FM over Nishnabotna Trib in Montgomery County, Iowa. It was built in 1949, so it is 76 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 3 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 29 vehicles a day, projected to reach 29 by 2044. The structure is 33 ft (10.1 m) long and 21 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesFM
CrossesNishnabotna Trib
Location072380303
RouteCounty Highway 0
CountyMontgomery County
StateIowa
Coordinates41.06677, -95.20226
Functional classRural Minor 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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMay 2024
Inspection intervalevery 12 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating4 US tons
Inventory rating0 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length33 ft (10.1 m)
Longest span32 ft (9.8 m)
Deck width21 ft (6.5 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic29 (2021)
Projected traffic29 by 2044
Trucks0%
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 FM over Nishnabotna Trib built?

It was built in 1949, making it 76 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 2024.

How much traffic does FM over Nishnabotna Trib carry?

About 29 vehicles per day (2021 count).

How long is FM over Nishnabotna Trib?

The structure is 33 ft (10.1 m) long with a longest span of 32 ft (9.8 m) and a deck 21 ft wide.

Who owns FM over Nishnabotna Trib?

It is owned by the County Highway Agency.