US Bridges

FM over Drainage Ditch

Fair

Humboldt County, Iowa · 091282301 · Structure no. 000000000184330

Built
1921
104 years old, rebuilt 1946
Condition
Fair
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
35 ft
1 main span
Daily traffic
529
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Drainage Ditch is a steel stringer/multi-beam or girder carrying FM over Drainage Ditch in Humboldt County, Iowa. It was built in 1921 and reconstructed in 1946, so it is 104 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 529 vehicles a day, roughly 11% of them trucks, projected to reach 529 by 2044. The structure is 35 ft (10.7 m) long and 24 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesFM
CrossesDrainage Ditch
Location091282301
RouteCounty Highway 0
CountyHumboldt County
StateIowa
Coordinates42.6883, -94.12484
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 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 alignment7: Better than present minimum criteria
Operating rating34.8 US tons
Inventory rating20.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length35 ft (10.7 m)
Longest span28 ft (8.5 m)
Deck width24 ft (7.3 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic529 (2022)
Projected traffic529 by 2044
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Drainage Ditch built?

It was built in 1921, making it 104 years old in 2025. It was reconstructed in 1946.

What condition is FM over Drainage Ditch 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 November 2024.

How much traffic does FM over Drainage Ditch carry?

About 529 vehicles per day (2022 count), of which roughly 11% are trucks.

How long is FM over Drainage Ditch?

The structure is 35 ft (10.7 m) long with a longest span of 28 ft (8.5 m) and a deck 24 ft wide.

Who owns FM over Drainage Ditch?

It is owned by the County Highway Agency.