FM over Marrowbone Creek

FairPosted for load

Carroll County, Iowa · 085330701 · Structure no. 000000000095940

Built: 1959; 66 years old
Condition: Fair; inspected July 2023
Type: Slab; Concrete Continuous
Length: 77 ft; 3 main spans
Daily traffic: 110; 2022 count
Owner: County; County Highway Agency

About this bridge

FM over Marrowbone Creek is a concrete continuous slab carrying FM over Marrowbone Creek in Carroll 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 6 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 110 vehicles a day, projected to reach 110 by 2043. The structure is 77 ft (23.5 m) long and 23 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps

CarriesFM

CrossesMarrowbone Creek

Location085330701

RouteCounty Highway 0

CountyCarroll County

StateIowa

Coordinates42.19531, -94.73279

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

Last inspectionJuly 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 geometry4: Meets minimum tolerable limits to be left in place as is

Waterway adequacy7: Better than present minimum criteria

Approach roadway alignment8: Equal to present desirable criteria

Operating rating36.7 US tons

Inventory rating22 US tons

Structure

Structure typeSlab

MaterialConcrete Continuous

DeckConcrete, cast-in-place

Main spans3

Design loadH 15

Structure length77 ft (23.5 m)

Longest span29 ft (8.8 m)

Deck width23 ft (6.9 m)

Roadway width20 ft (6.1 m)

Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic110 (2022)

Projected traffic110 by 2043

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 FM over Marrowbone Creek built?

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

What condition is FM over Marrowbone 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 July 2023.

How much traffic does FM over Marrowbone Creek carry?

About 110 vehicles per day (2022 count).

How long is FM over Marrowbone Creek?

The structure is 77 ft (23.5 m) long with a longest span of 29 ft (8.8 m) and a deck 23 ft wide.

Who owns FM over Marrowbone Creek?

It is owned by the County Highway Agency.