US Bridges

Ia 4 over W. Fork Des Moines River

Fair

Palo Alto County, Iowa · 3.2 Mi. S of S Jct. US 18 · Structure no. 000000000039220

Built
1958
67 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
325 ft
5 main spans
Daily traffic
2,460
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 4 over W. Fork Des Moines River is a steel continuous stringer/multi-beam or girder carrying Ia 4 over W. Fork Des Moines River in Palo Alto County, Iowa. It was built in 1958, so it is 67 years old, older 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 2,460 vehicles a day, roughly 16% of them trucks, projected to reach 2,460 by 2043. The structure is 325 ft (99.1 m) long and 34 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesIa 4
CrossesW. Fork Des Moines River
Location3.2 Mi. S of S Jct. US 18
RouteState Highway 4
CountyPalo Alto County
StateIowa
Coordinates43.06583, -94.67903
Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44.4 US tons
Inventory rating26.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadH 20
Structure length325 ft (99.1 m)
Longest span70 ft (21.3 m)
Deck width34 ft (10.4 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,460 (2022)
Projected traffic2,460 by 2043
Trucks16%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Ia 4 over W. Fork Des Moines River built?

It was built in 1958, making it 67 years old in 2025.

What condition is Ia 4 over W. Fork Des Moines River 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 August 2023.

How much traffic does Ia 4 over W. Fork Des Moines River carry?

About 2,460 vehicles per day (2022 count), of which roughly 16% are trucks.

How long is Ia 4 over W. Fork Des Moines River?

The structure is 325 ft (99.1 m) long with a longest span of 70 ft (21.3 m) and a deck 34 ft wide.

Who owns Ia 4 over W. Fork Des Moines River?

It is owned by the State Highway Agency.