US Bridges

FM over Nishnabotna Trib

Fair

Montgomery County, Iowa · 071380901 · Structure no. 000000000254630

Built
1959
66 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
95 ft
3 main spans
Daily traffic
72
2021 count
Owner
County
County Highway Agency

About this bridge

FM over Nishnabotna Trib is a prestressed concrete stringer/multi-beam or girder carrying FM over Nishnabotna Trib in Montgomery County, Iowa. It was built in 1959, so it is 66 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 72 vehicles a day, projected to reach 72 by 2043. The structure is 95 ft (29 m) long and 26 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesFM
CrossesNishnabotna Trib
Location071380901
RouteCounty Highway 0
CountyMontgomery County
StateIowa
Coordinates40.97359, -95.23106
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating47.8 US tons
Inventory rating35.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadH 15
Structure length95 ft (29 m)
Longest span31 ft (9.4 m)
Deck width26 ft (7.9 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic72 (2021)
Projected traffic72 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 1959, making it 66 years old in 2025.

What condition is FM over Nishnabotna Trib 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 May 2023.

How much traffic does FM over Nishnabotna Trib carry?

About 72 vehicles per day (2021 count).

How long is FM over Nishnabotna Trib?

The structure is 95 ft (29 m) long with a longest span of 31 ft (9.4 m) and a deck 26 ft wide.

Who owns FM over Nishnabotna Trib?

It is owned by the County Highway Agency.