US Bridges

FM 310th Ave over L Trumbull Outlet

Fair

Clay County, Iowa · 097352702 · Structure no. 000000000117280

Built
1970
55 years old
Condition
Fair
inspected March 2023
Type
Slab
Concrete Continuous
Length
78 ft
3 main spans
Daily traffic
968
2022 count
Owner
County
County Highway Agency

About this bridge

FM 310th Ave over L Trumbull Outlet is a concrete continuous slab carrying FM 310th Ave over L Trumbull Outlet in Clay County, Iowa. It was built in 1970, so it is 55 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 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 968 vehicles a day, roughly 16% of them trucks, projected to reach 968 by 2043. The structure is 78 ft (23.8 m) long and 32 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesFM 310th Ave
CrossesL Trumbull Outlet
Location097352702
RouteCounty Highway 0
CountyClay County
StateIowa
Coordinates43.19311, -94.97477
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMarch 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 alignment6: Equal to present minimum criteria
Operating rating50.9 US tons
Inventory rating29.3 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length78 ft (23.8 m)
Longest span29 ft (8.8 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic968 (2022)
Projected traffic968 by 2043
Trucks16%
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 statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM 310th Ave over L Trumbull Outlet built?

It was built in 1970, making it 55 years old in 2025.

What condition is FM 310th Ave over L Trumbull Outlet 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 310th Ave over L Trumbull Outlet carry?

About 968 vehicles per day (2022 count), of which roughly 16% are trucks.

How long is FM 310th Ave over L Trumbull Outlet?

The structure is 78 ft (23.8 m) long with a longest span of 29 ft (8.8 m) and a deck 32 ft wide.

Who owns FM 310th Ave over L Trumbull Outlet?

It is owned by the County Highway Agency.