US Bridges

FM S13 over Iowa River

Fair

Franklin County, Iowa · 091223103 · Structure no. 000000000157291

Built
1978
47 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
246 ft
3 main spans
Daily traffic
570
2022 count
Owner
County
County Highway Agency

About this bridge

FM S13 over Iowa River is a prestressed concrete stringer/multi-beam or girder carrying FM S13 over Iowa River in Franklin County, Iowa. It was built in 1978, so it is 47 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 570 vehicles a day, roughly 24% of them trucks, projected to reach 570 by 2043. The structure is 246 ft (75 m) long and 32 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesFM S13
CrossesIowa River
Location091223103
RouteCounty Highway 0
CountyFranklin County
StateIowa
Coordinates42.65368, -93.48826
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating85.1 US tons
Inventory rating34 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length246 ft (75 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 traffic570 (2022)
Projected traffic570 by 2043
Trucks24%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 S13 over Iowa River built?

It was built in 1978, making it 47 years old in 2025.

What condition is FM S13 over Iowa 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 2023.

How much traffic does FM S13 over Iowa River carry?

About 570 vehicles per day (2022 count), of which roughly 24% are trucks.

How long is FM S13 over Iowa River?

The structure is 246 ft (75 m) long with a longest span of 82 ft (25 m) and a deck 32 ft wide.

Who owns FM S13 over Iowa River?

It is owned by the County Highway Agency.