US Bridges

FM over Dd No. 1

Fair

Calhoun County, Iowa · 089331901 · Structure no. 000000000092650

Built
1964
61 years old, rebuilt 2018
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
57 ft
1 main span
Daily traffic
219
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Dd No. 1 is a prestressed concrete stringer/multi-beam or girder carrying FM over Dd No. 1 in Calhoun County, Iowa. It was built in 1964 and reconstructed in 2018, so it is 61 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 219 vehicles a day, roughly 31% of them trucks, projected to reach 219 by 2043. The structure is 57 ft (17.4 m) long and 30 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesFM
CrossesDd No. 1
Location089331901
RouteCounty Highway 0
CountyCalhoun County
StateIowa
Coordinates42.51718, -94.78207
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.
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 protection7 GoodSome minor problems.
Last inspectionJuly 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 adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating41.2 US tons
Inventory rating24.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length57 ft (17.4 m)
Longest span55 ft (16.8 m)
Deck width30 ft (9.2 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic219 (2022)
Projected traffic219 by 2043
Trucks31%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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$822,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Dd No. 1 built?

It was built in 1964, making it 61 years old in 2025. It was reconstructed in 2018.

What condition is FM over Dd No. 1 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 July 2023.

How much traffic does FM over Dd No. 1 carry?

About 219 vehicles per day (2022 count), of which roughly 31% are trucks.

How long is FM over Dd No. 1?

The structure is 57 ft (17.4 m) long with a longest span of 55 ft (16.8 m) and a deck 30 ft wide.

Who owns FM over Dd No. 1?

It is owned by the County Highway Agency.