US Bridges

US 18 over Little Floyd River

Fair

O'Brien County, Iowa · 0.1 MI W of E JCT SR L40 · Structure no. 000000000038230

Built
1957
68 years old
Condition
Fair
inspected November 2023
Type
Slab
Concrete Continuous
Length
122 ft
3 main spans
Daily traffic
4,230
2022 count
Owner
State
State Highway Agency

About this bridge

US 18 over Little Floyd River is a concrete continuous slab carrying US 18 over Little Floyd River in O'Brien County, Iowa. It was built in 1957, so it is 68 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 4,230 vehicles a day, roughly 18% of them trucks, projected to reach 4,230 by 2043. The structure is 122 ft (37.2 m) long and 35 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesUS 18
CrossesLittle Floyd River
Location0.1 MI W of E JCT SR L40
RouteU.S. Route 18
CountyO'Brien County
StateIowa
Coordinates43.1861, -95.72544
Functional classRural Principal Arterial - Other

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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating53.5 US tons
Inventory rating32.1 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length122 ft (37.2 m)
Longest span46 ft (14 m)
Deck width35 ft (10.6 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,230 (2022)
Projected traffic4,230 by 2043
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 US 18 over Little Floyd River built?

It was built in 1957, making it 68 years old in 2025.

What condition is US 18 over Little Floyd River 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 November 2023.

How much traffic does US 18 over Little Floyd River carry?

About 4,230 vehicles per day (2022 count), of which roughly 18% are trucks.

How long is US 18 over Little Floyd River?

The structure is 122 ft (37.2 m) long with a longest span of 46 ft (14 m) and a deck 35 ft wide.

Who owns US 18 over Little Floyd River?

It is owned by the State Highway Agency.