US Bridges

Local over Dd 12

Poor

Calhoun County, Iowa · 089312801 · Structure no. 000000000092481

Built
1974
51 years old
Condition
Poor
inspected August 2023
Type
Channel Beam
Concrete
Length
31 ft
1 main span
Daily traffic
26
2022 count
Owner
County
County Highway Agency

About this bridge

Local over Dd 12 is a concrete channel beam carrying Local over Dd 12 in Calhoun County, Iowa. It was built in 1974, so it is 51 years old, older than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 26 vehicles a day, projected to reach 26 by 2043. The structure is 31 ft (9.4 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 12
Location089312801
RouteCounty Highway 0
CountyCalhoun County
StateIowa
Coordinates42.50258, -94.51876
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

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.
Substructure4 PoorAdvanced section loss, deterioration, 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 evaluation4: Meets minimum tolerable limits to be 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 rating41.6 US tons
Inventory rating30.5 US tons

Structure

Structure typeChannel Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length31 ft (9.4 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 traffic26 (2022)
Projected traffic26 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 12 built?

It was built in 1974, making it 51 years old in 2025.

What condition is Local over Dd 12 in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in August 2023.

How much traffic does Local over Dd 12 carry?

About 26 vehicles per day (2022 count).

How long is Local over Dd 12?

The structure is 31 ft (9.4 m) long with a longest span of 28 ft (8.5 m) and a deck 32 ft wide.

Who owns Local over Dd 12?

It is owned by the County Highway Agency.