US Bridges

FM over Skunk River

Poor

Washington County, Iowa · 074091004 · Structure no. 000000000336060

Built
1957
68 years old
Condition
Poor
inspected February 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
653 ft
6 main spans
Daily traffic
120
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Skunk River is a steel continuous stringer/multi-beam or girder carrying FM over Skunk River in Washington County, Iowa. It was built in 1957, so it is 68 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 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 120 vehicles a day, roughly 20% of them trucks, projected to reach 120 by 2043. The structure is 653 ft (199 m) long and 22 ft wide. If it were closed, the detour would be 19.3 mi (31 km).

CarriesFM
CrossesSkunk River
Location074091004
RouteCounty Highway 0
StateIowa
Coordinates41.22605, -91.88791
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionFebruary 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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating32.7 US tons
Inventory rating19.6 US tons

Structure

MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans6
Design loadH 15
Structure length653 ft (199 m)
Longest span117 ft (35.7 m)
Deck width22 ft (6.7 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic120 (2022)
Projected traffic120 by 2043
Trucks20%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed19.3 mi (31 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 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 Skunk River built?

It was built in 1957, making it 68 years old in 2025.

What condition is FM over Skunk River 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 February 2023.

How much traffic does FM over Skunk River carry?

About 120 vehicles per day (2022 count), of which roughly 20% are trucks.

How long is FM over Skunk River?

The structure is 653 ft (199 m) long with a longest span of 117 ft (35.7 m) and a deck 22 ft wide.

Who owns FM over Skunk River?

It is owned by the County Highway Agency.