US Bridges

FM over Dd

Poor

Calhoun County, Iowa · 088321901 · Structure no. 000000000091951

Built
1973
52 years old
Condition
Poor
inspected July 2024
Type
Channel Beam
Concrete
Length
31 ft
1 main span
Daily traffic
30
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Dd is a concrete channel beam carrying FM over Dd 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 poor condition with a lowest component rating of 3 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. Its operating status is: open, posting recommended but not legally implemented.

It carries about 30 vehicles a day, projected to reach 30 by 2044. 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
CarriesFM
CrossesDd
Location088321901
RouteCounty Highway 0
CountyCalhoun County
StateIowa
Coordinates42.42787, -94.62361
Functional classRural Minor Collector

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.
Substructure3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2024
Inspection intervalevery 12 months
Operating statusOpen, posting recommended but not legally implemented
ScourFoundations stable; scour above top of footing
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry7: Better than present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating20.6 US tons
Inventory rating12.3 US tons

Structure

Structure typeChannel Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length31 ft (9.4 m)
Longest span29 ft (8.8 m)
Deck width32 ft (9.8 m)
Roadway width31 ft (9.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic30 (2022)
Projected traffic30 by 2044
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$515,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Dd built?

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

What condition is FM over Dd 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 July 2024.

How much traffic does FM over Dd carry?

About 30 vehicles per day (2022 count).

How long is FM over Dd?

The structure is 31 ft (9.4 m) long with a longest span of 29 ft (8.8 m) and a deck 32 ft wide.

Who owns FM over Dd?

It is owned by the County Highway Agency.