FM over Walnut Creek

Good

Marion County, Iowa · 75183200 · Structure no. 000000000239771

Built: 2009; 16 years old
Condition: Good; inspected December 2022
Type: Slab; Concrete Continuous
Length: 113 ft; 3 main spans
Daily traffic: 1,280; 2022 count
Owner: County; County Highway Agency

About this bridge

FM over Walnut Creek is a concrete continuous slab carrying FM over Walnut Creek in Marion County, Iowa. It was built in 2009, so it is 16 years old, younger than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 1,280 vehicles a day, roughly 13% of them trucks, projected to reach 1,280 by 2043. The structure is 113 ft (34.4 m) long and 33 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesFM

CrossesWalnut Creek

Location75183200

RouteCounty Highway 0

CountyMarion County

StateIowa

Coordinates41.26074, -92.95679

Functional classRural Major Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

Component	Rating	Meaning
Deck	8 Very Good	No problems noted.
Superstructure	8 Very Good	No problems noted.
Substructure	8 Very Good	No problems noted.
Channel and channel protection	7 Good	Some minor problems.

Last inspectionDecember 2022

Inspection intervalevery 48 months

Operating statusOpen, no restriction

ScourFoundations stable; scour above top of footing

Structural evaluation8: Equal to present desirable criteria

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

Waterway adequacy8: Equal to present desirable criteria

Approach roadway alignment7: Better than present minimum criteria

Operating rating73.4 US tons

Inventory rating44.1 US tons

Structure

Structure typeSlab

MaterialConcrete Continuous

DeckConcrete, cast-in-place

Main spans3

Design loadHL 93

Structure length113 ft (34.4 m)

Longest span43 ft (13.1 m)

Deck width33 ft (10 m)

Roadway width30 ft (9.1 m)

Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,280 (2022)

Projected traffic1,280 by 2043

Trucks13%

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 proposedOther structural work, including hydraulic replacements

Estimated improvement cost—

NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Walnut Creek built?

It was built in 2009, making it 16 years old in 2025.

What condition is FM over Walnut Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in December 2022.

How much traffic does FM over Walnut Creek carry?

About 1,280 vehicles per day (2022 count), of which roughly 13% are trucks.

How long is FM over Walnut Creek?

The structure is 113 ft (34.4 m) long with a longest span of 43 ft (13.1 m) and a deck 33 ft wide.

Who owns FM over Walnut Creek?

It is owned by the County Highway Agency.