US Bridges

Local over Dd 12

Fair

Calhoun County, Iowa · 089313601 · Structure no. 000000000092501

Built
1973
52 years old
Condition
Fair
inspected August 2023
Type
Tee Beam
Prestressed Concrete
Length
43 ft
1 main span
Daily traffic
34
2022 count
Owner
County
County Highway Agency

About this bridge

Local over Dd 12 is a prestressed concrete tee beam carrying Local over Dd 12 in Calhoun County, Iowa. It was built in 1973, so it is 52 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 34 vehicles a day, projected to reach 34 by 2043. The structure is 43 ft (13.1 m) long and 32 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesLocal
CrossesDd 12
Location089313601
RouteCounty Highway 0
CountyCalhoun County
StateIowa
Coordinates42.48781, -94.45285
Functional classRural Local

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 inspectionAugust 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 geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating73.6 US tons
Inventory rating19 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length43 ft (13.1 m)
Longest span40 ft (12.2 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic34 (2022)
Projected traffic34 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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$644,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Local over Dd 12 built?

It was built in 1973, making it 52 years old in 2025.

What condition is Local over Dd 12 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 2023.

How much traffic does Local over Dd 12 carry?

About 34 vehicles per day (2022 count).

How long is Local over Dd 12?

The structure is 43 ft (13.1 m) long with a longest span of 40 ft (12.2 m) and a deck 32 ft wide.

Who owns Local over Dd 12?

It is owned by the County Highway Agency.