US Bridges

FM 335th ST over Boyer River

Fair

Harrison County, Iowa · 078442301 · Structure no. 000000000177730

Built
1959
66 years old
Condition
Fair
inspected January 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
252 ft
3 main spans
Daily traffic
788
2022 count
Owner
County
County Highway Agency

About this bridge

FM 335th ST over Boyer River is a steel continuous stringer/multi-beam or girder carrying FM 335th ST over Boyer River in Harrison County, Iowa. It was built in 1959, so it is 66 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 788 vehicles a day, roughly 10% of them trucks, projected to reach 788 by 2044. The structure is 252 ft (76.8 m) long and 28 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesFM 335th ST
CrossesBoyer River
Location078442301
RouteCounty Highway 0
CountyHarrison County
StateIowa
Coordinates41.54915, -95.87218
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJanuary 2024
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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating45.5 US tons
Inventory rating27.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 15
Structure length252 ft (76.8 m)
Longest span98 ft (29.9 m)
Deck width28 ft (8.6 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic788 (2022)
Projected traffic788 by 2044
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM 335th ST over Boyer River built?

It was built in 1959, making it 66 years old in 2025.

What condition is FM 335th ST 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 January 2024.

How much traffic does FM 335th ST over Boyer River carry?

About 788 vehicles per day (2022 count), of which roughly 10% are trucks.

How long is FM 335th ST over Boyer River?

The structure is 252 ft (76.8 m) long with a longest span of 98 ft (29.9 m) and a deck 28 ft wide.

Who owns FM 335th ST over Boyer River?

It is owned by the County Highway Agency.