US Bridges

FM over South River

Fair

Warren County, Iowa · 076233504 · Structure no. 000000000334430

Built
1979
46 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
229 ft
3 main spans
Daily traffic
1,330
2022 count
Owner
County
County Highway Agency

About this bridge

FM over South River is a prestressed concrete stringer/multi-beam or girder carrying FM over South River in Warren County, Iowa. It was built in 1979, so it is 46 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 5 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 1,330 vehicles a day, roughly 12% of them trucks, projected to reach 1,330 by 2044. The structure is 229 ft (69.8 m) long and 32 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

CarriesFM
CrossesSouth River
Location076233504
RouteCounty Highway 0
StateIowa
Coordinates41.3473, -93.46306
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating80.8 US tons
Inventory rating34 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length229 ft (69.8 m)
Longest span82 ft (25 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,330 (2022)
Projected traffic1,330 by 2044
Trucks12%
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 South River built?

It was built in 1979, making it 46 years old in 2025.

What condition is FM over South 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 October 2024.

How much traffic does FM over South River carry?

About 1,330 vehicles per day (2022 count), of which roughly 12% are trucks.

How long is FM over South River?

The structure is 229 ft (69.8 m) long with a longest span of 82 ft (25 m) and a deck 32 ft wide.

Who owns FM over South River?

It is owned by the County Highway Agency.