US Bridges

Iris Ave over Drainage Ditch

Poor

Howard County, Iowa · 097130902 · Structure no. 000000000181830

Built
1966
59 years old
Condition
Poor
inspected April 2024
Type
Channel Beam
Concrete
Length
26 ft
1 main span
Daily traffic
21
2021 count
Owner
County
County Highway Agency

About this bridge

Iris Ave over Drainage Ditch is a concrete channel beam carrying Iris Ave over Drainage Ditch in Howard County, Iowa. It was built in 1966, so it is 59 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.

It carries about 21 vehicles a day, projected to reach 21 by 2044. The structure is 26 ft (7.9 m) long and 29 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

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CarriesIris Ave
CrossesDrainage Ditch
Location097130902
RouteCounty Highway 0
CountyHoward County
StateIowa
Coordinates43.23637, -92.39704
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 inspectionApril 2024
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating45.3 US tons
Inventory rating28.7 US tons

Structure

Structure typeChannel Beam
MaterialConcrete
DeckConcrete, precast panels
Main spans1
Design loadUnknown
Structure length26 ft (7.9 m)
Longest span24 ft (7.3 m)
Deck width29 ft (8.9 m)
Roadway width28 ft (8.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic21 (2021)
Projected traffic21 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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—
NavigationNo navigation control on waterway

Frequently asked questions

When was Iris Ave over Drainage Ditch built?

It was built in 1966, making it 59 years old in 2025.

What condition is Iris Ave over Drainage Ditch 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 April 2024.

How much traffic does Iris Ave over Drainage Ditch carry?

About 21 vehicles per day (2021 count).

How long is Iris Ave over Drainage Ditch?

The structure is 26 ft (7.9 m) long with a longest span of 24 ft (7.3 m) and a deck 29 ft wide.

Who owns Iris Ave over Drainage Ditch?

It is owned by the County Highway Agency.