US Bridges

Local over Dd No 12

Fair

Calhoun County, Iowa · 089312102 · Structure no. 000000000092451

Built
1976
49 years old
Condition
Fair
inspected August 2023
Type
Channel Beam
Concrete
Length
32 ft
1 main span
Daily traffic
60
2022 count
Owner
County
County Highway Agency

About this bridge

Local over Dd No 12 is a concrete channel beam carrying Local over Dd No 12 in Calhoun County, Iowa. It was built in 1976, so it is 49 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 60 vehicles a day, projected to reach 60 by 2043. The structure is 32 ft (9.8 m) long and 32 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesLocal
CrossesDd No 12
Location089312102
RouteCounty Highway 0
CountyCalhoun County
StateIowa
Coordinates42.50394, -94.52092
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 rating51.5 US tons
Inventory rating30.9 US tons

Structure

Structure typeChannel Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length32 ft (9.8 m)
Longest span28 ft (8.5 m)
Deck width32 ft (9.8 m)
Roadway width31 ft (9.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic60 (2022)
Projected traffic60 by 2043
Trucks0%
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$525,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Local over Dd No 12 built?

It was built in 1976, making it 49 years old in 2025.

What condition is Local over Dd No 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 No 12 carry?

About 60 vehicles per day (2022 count).

How long is Local over Dd No 12?

The structure is 32 ft (9.8 m) long with a longest span of 28 ft (8.5 m) and a deck 32 ft wide.

Who owns Local over Dd No 12?

It is owned by the County Highway Agency.