FM over Otter Creek

FairPosted for load

Louisa County, Iowa · 073030403 · Structure no. 000000000223610

Built: 1959; 66 years old
Condition: Fair; inspected June 2023
Type: Slab; Concrete Continuous
Length: 100 ft; 3 main spans
Daily traffic: 50; 2022 count
Owner: County; County Highway Agency

About this bridge

FM over Otter Creek is a concrete continuous slab carrying FM over Otter Creek in Louisa County, Iowa. It was built in 1959, so it is 66 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. Its operating status is: posted for load restriction.

It carries about 50 vehicles a day, projected to reach 50 by 2043. The structure is 100 ft (30.5 m) long and 23 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesFM

CrossesOtter Creek

Location073030403

RouteCounty Highway 0

CountyLouisa County

StateIowa

Coordinates41.15371, -91.20074

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.

Component	Rating	Meaning
Deck	5 Fair	All primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure	5 Fair	All primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure	6 Satisfactory	Structural elements show some minor deterioration.
Channel and channel protection	7 Good	Some minor problems.

Last inspectionJune 2023

Inspection intervalevery 24 months

Operating statusPosted for load restriction

ScourFoundations stable; scour above top of footing

Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is

Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is

Waterway adequacy7: Better than present minimum criteria

Approach roadway alignment7: Better than present minimum criteria

Operating rating32.1 US tons

Inventory rating19.3 US tons

Structure

Structure typeSlab

MaterialConcrete Continuous

DeckConcrete, cast-in-place

Main spans3

Design loadH 15

Structure length100 ft (30.5 m)

Longest span39 ft (11.9 m)

Deck width23 ft (6.9 m)

Roadway width20 ft (6.1 m)

Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2022)

Projected traffic50 by 2043

Trucks0%

Lanes on structure2

Traffic directionTwo-way traffic

CarriesHighway

CrossesWaterway

Detour if closed1.9 mi (3 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 proposedOther structural work, including hydraulic replacements

Estimated improvement cost—

NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Otter Creek built?

It was built in 1959, making it 66 years old in 2025.

What condition is FM over Otter Creek 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 June 2023.

How much traffic does FM over Otter Creek carry?

About 50 vehicles per day (2022 count).

How long is FM over Otter Creek?

The structure is 100 ft (30.5 m) long with a longest span of 39 ft (11.9 m) and a deck 23 ft wide.

Who owns FM over Otter Creek?

It is owned by the County Highway Agency.