US Bridges

FM 320th ST over Dd #28

Fair

Clay County, Iowa · 097363201 · Structure no. 000000000117451

Built
1996
29 years old
Condition
Fair
inspected March 2023
Type
Culvert
Steel
Length
30 ft
3 main spans
Daily traffic
1,228
2022 count
Owner
County
County Highway Agency

About this bridge

FM 320th ST over Dd #28 is a steel culvert carrying FM 320th ST over Dd #28 in Clay County, Iowa. It was built in 1996, so it is 29 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 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 1,228 vehicles a day, projected to reach 1,228 by 2043. The structure is 30 ft (9.1 m) long. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesFM 320th ST
CrossesDd #28
Location097363201
RouteCounty Highway 0
CountyClay County
StateIowa
Coordinates43.18369, -95.12428
Functional classRural Major 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
Channel and channel protection7 GoodSome minor problems.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating107.1 US tons
Inventory rating107.1 US tons

Structure

Structure typeCulvert
MaterialSteel
DeckNot applicable
Main spans3
Design loadH 20
Structure length30 ft (9.1 m)
Longest span8 ft (2.4 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,228 (2022)
Projected traffic1,228 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 FM 320th ST over Dd #28 built?

It was built in 1996, making it 29 years old in 2025.

What condition is FM 320th ST over Dd #28 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 March 2023.

How much traffic does FM 320th ST over Dd #28 carry?

About 1,228 vehicles per day (2022 count).

How long is FM 320th ST over Dd #28?

The structure is 30 ft (9.1 m) long with a longest span of 8 ft (2.4 m).

Who owns FM 320th ST over Dd #28?

It is owned by the County Highway Agency.