US Bridges

FM over Overflow N.River

Fair

Madison County, Iowa · 077273602 · Structure no. 000000000234900

Built
1961
64 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
44 ft
1 main span
Daily traffic
50
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Overflow N.River is a prestressed concrete stringer/multi-beam or girder carrying FM over Overflow N.River in Madison County, Iowa. It was built in 1961, so it is 64 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 50 vehicles a day, roughly 32% of them trucks, projected to reach 50 by 2043. The structure is 44 ft (13.4 m) long and 26 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesFM
CrossesOverflow N.River
Location077273602
RouteCounty Highway 0
CountyMadison County
StateIowa
Coordinates41.4232, -93.91321
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 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 geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating41.6 US tons
Inventory rating26.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length44 ft (13.4 m)
Longest span43 ft (13.1 m)
Deck width26 ft (7.9 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2022)
Projected traffic50 by 2043
Trucks32%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 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$405,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Overflow N.River built?

It was built in 1961, making it 64 years old in 2025.

What condition is FM over Overflow N.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 August 2023.

How much traffic does FM over Overflow N.River carry?

About 50 vehicles per day (2022 count), of which roughly 32% are trucks.

How long is FM over Overflow N.River?

The structure is 44 ft (13.4 m) long with a longest span of 43 ft (13.1 m) and a deck 26 ft wide.

Who owns FM over Overflow N.River?

It is owned by the County Highway Agency.