US Bridges

FM over Rock Creek

Poor

Woodbury County, Iowa · 088430603 · Structure no. 000000000353155

Built
1900
125 years old
Condition
Poor
inspected July 2024
Type
Arch - Deck
Concrete
Length
20 ft
1 main span
Daily traffic
199
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Rock Creek is a concrete arch - deck carrying FM over Rock Creek in Woodbury County, Iowa. It was built in 1900, so it is 125 years old, older 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 3 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 199 vehicles a day, roughly 10% of them trucks, projected to reach 199 by 2044. The structure is 20 ft (6.1 m) long and 40 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

CarriesFM
CrossesRock Creek
Location088430603
RouteCounty Highway 0
StateIowa
Coordinates42.47504, -95.89551
Functional classRural Minor 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
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Channel and channel protection3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry9: Superior to present desirable criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating23 US tons
Inventory rating19 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckNot applicable
Main spans1
Design loadUnknown
Structure length20 ft (6.1 m)
Longest span20 ft (6.1 m)
Deck width40 ft (12.2 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic199 (2022)
Projected traffic199 by 2044
Trucks10%
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 statusPossibly eligible for the National Register; requires further investigation
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Rock Creek built?

It was built in 1900, making it 125 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 July 2024.

How much traffic does FM over Rock Creek carry?

About 199 vehicles per day (2022 count), of which roughly 10% are trucks.

How long is FM over Rock Creek?

The structure is 20 ft (6.1 m) long with a longest span of 20 ft (6.1 m) and a deck 40 ft wide.

Who owns FM over Rock Creek?

It is owned by the County Highway Agency.