FM over Rock Creek

Fair

Benton County, Iowa · 085120501 · Structure no. 000000000072841

Built: 1987; 38 years old
Condition: Fair; inspected May 2023
Type: Slab; Concrete Continuous
Length: 103 ft; 3 main spans
Daily traffic: 20; 2021 count
Owner: County; County Highway Agency

About this bridge

FM over Rock Creek is a concrete continuous slab carrying FM over Rock Creek in Benton County, Iowa. It was built in 1987, so it is 38 years old, younger 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 20 vehicles a day, projected to reach 20 by 2043. The structure is 103 ft (31.4 m) long and 33 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesFM

CrossesRock Creek

Location085120501

RouteCounty Highway 0

CountyBenton County

StateIowa

Coordinates42.2108, -92.26094

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

Last inspectionMay 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 geometry7: Better than present minimum criteria

Waterway adequacy8: Equal to present desirable criteria

Approach roadway alignment6: Equal to present minimum criteria

Operating rating54.7 US tons

Inventory rating34 US tons

Structure

Structure typeSlab

MaterialConcrete Continuous

DeckConcrete, cast-in-place

Main spans3

Design loadH 20

Structure length103 ft (31.4 m)

Longest span39 ft (11.9 m)

Deck width33 ft (10.1 m)

Roadway width30 ft (9.1 m)

Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20 (2021)

Projected traffic20 by 2043

Trucks0%

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 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 Rock Creek built?

It was built in 1987, making it 38 years old in 2025.

What condition is FM over Rock 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 May 2023.

How much traffic does FM over Rock Creek carry?

About 20 vehicles per day (2021 count).

How long is FM over Rock Creek?

The structure is 103 ft (31.4 m) long with a longest span of 39 ft (11.9 m) and a deck 33 ft wide.

Who owns FM over Rock Creek?

It is owned by the County Highway Agency.