US Bridges

Local over Dd 20

PoorPosted for load

Calhoun County, Iowa · 088322402 · Structure no. 000000000092000

Built
1948
77 years old
Condition
Poor
inspected July 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
65 ft
1 main span
Daily traffic
26
2022 count
Owner
County
County Highway Agency

About this bridge

Local over Dd 20 is a steel stringer/multi-beam or girder carrying Local over Dd 20 in Calhoun County, Iowa. It was built in 1948, so it is 77 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: posted for other load-capacity restriction.

It carries about 26 vehicles a day, projected to reach 26 by 2044. The structure is 65 ft (19.8 m) long and 23 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesLocal
CrossesDd 20
Location088322402
RouteCounty Highway 0
CountyCalhoun County
StateIowa
Coordinates42.42418, -94.53383
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2024
Inspection intervalevery 12 months
Operating statusPosted for other load-capacity restriction
ScourFoundations stable; scour above top of footing
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating29.8 US tons
Inventory rating20.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length65 ft (19.8 m)
Longest span61 ft (18.6 m)
Deck width23 ft (7.1 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic26 (2022)
Projected traffic26 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$891,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Local over Dd 20 built?

It was built in 1948, making it 77 years old in 2025.

What condition is Local over Dd 20 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 Local over Dd 20 carry?

About 26 vehicles per day (2022 count).

How long is Local over Dd 20?

The structure is 65 ft (19.8 m) long with a longest span of 61 ft (18.6 m) and a deck 23 ft wide.

Who owns Local over Dd 20?

It is owned by the County Highway Agency.