US Bridges

FM over Boyer River

Fair

Sac County, Iowa · 088370801 · Structure no. 000000000300971

Built
1975
50 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
179 ft
3 main spans
Daily traffic
100
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Boyer River is a prestressed concrete stringer/multi-beam or girder carrying FM over Boyer River in Sac County, Iowa. It was built in 1975, so it is 50 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 100 vehicles a day, roughly 11% of them trucks, projected to reach 100 by 2044. The structure is 179 ft (54.6 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
CrossesBoyer River
Location088370801
RouteCounty Highway 0
CountySac County
StateIowa
Coordinates42.45802, -95.1726
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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating73.6 US tons
Inventory rating40 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length179 ft (54.6 m)
Longest span65 ft (19.8 m)
Deck width32 ft (9.8 m)
Roadway width31 ft (9.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2022)
Projected traffic100 by 2044
Trucks11%
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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Boyer River built?

It was built in 1975, making it 50 years old in 2025.

What condition is FM over Boyer 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 2024.

How much traffic does FM over Boyer River carry?

About 100 vehicles per day (2022 count), of which roughly 11% are trucks.

How long is FM over Boyer River?

The structure is 179 ft (54.6 m) long with a longest span of 65 ft (19.8 m) and a deck 32 ft wide.

Who owns FM over Boyer River?

It is owned by the County Highway Agency.