US Bridges

Zinnia Ave over Small Stream

Fair

Mitchell County, Iowa · 100181902 · Structure no. 000000000362390

Built
1984
41 years old
Condition
Fair
inspected December 2023
Type
Tee Beam
Concrete
Length
31 ft
1 main span
Daily traffic
167
2022 count
Owner
County
County Highway Agency

About this bridge

Zinnia Ave over Small Stream is a concrete tee beam carrying Zinnia Ave over Small Stream in Mitchell County, Iowa. It was built in 1984, so it is 41 years old, younger 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 167 vehicles a day, roughly 28% of them trucks, projected to reach 167 by 2043. The structure is 31 ft (9.4 m) long and 32 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

Location

Open in Google Maps
CarriesZinnia Ave
CrossesSmall Stream
Location100181902
RouteCounty Highway 0
CountyMitchell County
StateIowa
Coordinates43.47213, -93.0245
Functional classRural Minor Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionDecember 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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment9: Superior to present desirable criteria
Operating rating88 US tons
Inventory rating43 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length31 ft (9.4 m)
Longest span30 ft (9.1 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic167 (2022)
Projected traffic167 by 2043
Trucks28%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.9 mi (24 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 Zinnia Ave over Small Stream built?

It was built in 1984, making it 41 years old in 2025.

What condition is Zinnia Ave over Small Stream 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 December 2023.

How much traffic does Zinnia Ave over Small Stream carry?

About 167 vehicles per day (2022 count), of which roughly 28% are trucks.

How long is Zinnia Ave over Small Stream?

The structure is 31 ft (9.4 m) long with a longest span of 30 ft (9.1 m) and a deck 32 ft wide.

Who owns Zinnia Ave over Small Stream?

It is owned by the County Highway Agency.