US Bridges

FM over I-29

Fair

Monona County, Iowa · 4.3 Mi. N of Jct. SR E24 · Structure no. 000000000037370

Built
1959
66 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
218 ft
4 main spans
Daily traffic
79
2022 count
Owner
State
State Highway Agency

About this bridge

FM over I-29 is a prestressed concrete stringer/multi-beam or girder carrying FM over I-29 in Monona 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 79 vehicles a day, projected to reach 79 by 2044. The structure is 218 ft (66.4 m) long and 29 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesFM
CrossesI-29
Location4.3 Mi. N of Jct. SR E24
RouteCounty Highway 0
CountyMonona County
StateIowa
Coordinates42.18554, -96.23688
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating54.3 US tons
Inventory rating16 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadH 20
Structure length218 ft (66.4 m)
Longest span65 ft (19.8 m)
Deck width29 ft (8.7 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic79 (2022)
Projected traffic79 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed3.7 mi (6 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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was FM over I-29 built?

It was built in 1959, making it 66 years old in 2025.

What condition is FM over I-29 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 October 2024.

How much traffic does FM over I-29 carry?

About 79 vehicles per day (2022 count).

How long is FM over I-29?

The structure is 218 ft (66.4 m) long with a longest span of 65 ft (19.8 m) and a deck 29 ft wide.

Who owns FM over I-29?

It is owned by the State Highway Agency.