US Bridges

FM over Sioux River

Poor

Monona County, Iowa · 084452511 · Structure no. 000000000250920

Built
1960
65 years old
Condition
Poor
inspected May 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
57 ft
1 main span
Daily traffic
45
2021 count
Owner
County
County Highway Agency

About this bridge

FM over Sioux River is a prestressed concrete stringer/multi-beam or girder carrying FM over Sioux River in Monona County, Iowa. It was built in 1960, so it is 65 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 45 vehicles a day, projected to reach 45 by 2043. The structure is 57 ft (17.4 m) long and 22 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesFM
CrossesSioux River
Location084452511
RouteCounty Highway 0
CountyMonona County
StateIowa
Coordinates42.05657, -96.023
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating41.6 US tons
Inventory rating18.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length57 ft (17.4 m)
Longest span55 ft (16.8 m)
Deck width22 ft (6.7 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic45 (2021)
Projected traffic45 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 Sioux River built?

It was built in 1960, making it 65 years old in 2025.

What condition is FM over Sioux 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 May 2023.

How much traffic does FM over Sioux River carry?

About 45 vehicles per day (2021 count).

How long is FM over Sioux River?

The structure is 57 ft (17.4 m) long with a longest span of 55 ft (16.8 m) and a deck 22 ft wide.

Who owns FM over Sioux River?

It is owned by the County Highway Agency.