US Bridges

FM over Rock Creek

Poor

Benton County, Iowa · 086122401 · Structure no. 000000000073631

Built
1985
40 years old
Condition
Poor
inspected April 2023
Type
Slab
Concrete Continuous
Length
103 ft
3 main spans
Daily traffic
430
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 1985, so it is 40 years old, younger than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 430 vehicles a day, roughly 8% of them trucks, projected to reach 430 by 2043. The structure is 103 ft (31.4 m) long and 32 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesFM
CrossesRock Creek
Location086122401
RouteCounty Highway 0
CountyBenton County
StateIowa
Coordinates42.25409, -92.18721
Functional classRural Major Collector

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating54.9 US tons
Inventory rating33.1 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 width32 ft (9.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic430 (2021)
Projected traffic430 by 2043
Trucks8%
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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Rock Creek built?

It was built in 1985, making it 40 years old in 2025.

What condition is FM over Rock Creek in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in April 2023.

How much traffic does FM over Rock Creek carry?

About 430 vehicles per day (2021 count), of which roughly 8% are trucks.

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 32 ft wide.

Who owns FM over Rock Creek?

It is owned by the County Highway Agency.