US Bridges

FM over Iowa River

Poor

Marshall County, Iowa · 083170104 · Structure no. 000000000242300

Built
1953
72 years old, rebuilt 1981
Condition
Poor
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
536 ft
5 main spans
Daily traffic
1,365
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Iowa River is a steel continuous stringer/multi-beam or girder carrying FM over Iowa River in Marshall County, Iowa. It was built in 1953 and reconstructed in 1981, so it is 72 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.

It carries about 1,365 vehicles a day, roughly 19% of them trucks, projected to reach 1,365 by 2044. The structure is 536 ft (163.4 m) long and 32 ft wide. If it were closed, the detour would be 16.2 mi (26 km).

CarriesFM
CrossesIowa River
Location083170104
RouteCounty Highway 0
StateIowa
Coordinates42.02958, -92.78449
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no 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 adequacy7: Better than present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating29.3 US tons
Inventory rating17.6 US tons

Structure

MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadH 15
Structure length536 ft (163.4 m)
Longest span117 ft (35.7 m)
Deck width32 ft (9.9 m)
Roadway width31 ft (9.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,365 (2022)
Projected traffic1,365 by 2044
Trucks19%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed16.2 mi (26 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 Iowa River built?

It was built in 1953, making it 72 years old in 2025. It was reconstructed in 1981.

What condition is FM over Iowa River 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 November 2024.

How much traffic does FM over Iowa River carry?

About 1,365 vehicles per day (2022 count), of which roughly 19% are trucks.

How long is FM over Iowa River?

The structure is 536 ft (163.4 m) long with a longest span of 117 ft (35.7 m) and a deck 32 ft wide.

Who owns FM over Iowa River?

It is owned by the County Highway Agency.