US Bridges

FM over Des Moines River

Fair

Boone County, Iowa · 084271307 · Structure no. 000000000077801

Built
1980
45 years old
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
724 ft
8 main spans
Daily traffic
1,028
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Des Moines River is a steel continuous stringer/multi-beam or girder carrying FM over Des Moines River in Boone County, Iowa. It was built in 1980, so it is 45 years old, younger 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 1,028 vehicles a day, roughly 7% of them trucks, projected to reach 1,028 by 2044. The structure is 724 ft (220.7 m) long and 32 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesFM
CrossesDes Moines River
Location084271307
RouteCounty Highway 0
CountyBoone County
StateIowa
Coordinates42.08079, -93.93942
Functional classRural Major 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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating50.2 US tons
Inventory rating30.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans8
Design loadH 20
Structure length724 ft (220.7 m)
Longest span117 ft (35.7 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,028 (2022)
Projected traffic1,028 by 2044
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Des Moines River built?

It was built in 1980, making it 45 years old in 2025.

What condition is FM over Des Moines 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 May 2024.

How much traffic does FM over Des Moines River carry?

About 1,028 vehicles per day (2022 count), of which roughly 7% are trucks.

How long is FM over Des Moines River?

The structure is 724 ft (220.7 m) long with a longest span of 117 ft (35.7 m) and a deck 32 ft wide.

Who owns FM over Des Moines River?

It is owned by the County Highway Agency.