US Bridges

340th over Small Stream

Fair

Mitchell County, Iowa · 097160401 · Structure no. 000000000247371

Built
1974
51 years old
Condition
Fair
inspected January 2024
Type
Slab
Concrete
Length
33 ft
1 main span
Daily traffic
33
2022 count
Owner
County
County Highway Agency

About this bridge

340th over Small Stream is a concrete slab carrying 340th over Small Stream in Mitchell 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 fair condition with a lowest component rating of 6 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 33 vehicles a day, projected to reach 33 by 2044. The structure is 33 ft (10.1 m) long and 32 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
Carries340th
CrossesSmall Stream
Location097160401
RouteCounty Highway 0
CountyMitchell County
StateIowa
Coordinates43.25534, -92.74482
Functional classRural Local

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.
Superstructure8 Very GoodNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating74 US tons
Inventory rating39 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length33 ft (10.1 m)
Longest span30 ft (9.1 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic33 (2022)
Projected traffic33 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 340th over Small Stream built?

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

What condition is 340th 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 January 2024.

How much traffic does 340th over Small Stream carry?

About 33 vehicles per day (2022 count).

How long is 340th over Small Stream?

The structure is 33 ft (10.1 m) long with a longest span of 30 ft (9.1 m) and a deck 32 ft wide.

Who owns 340th over Small Stream?

It is owned by the County Highway Agency.