US Bridges

US 18 over West Fork Iowa River

Fair

Hancock County, Iowa · 2.8 Mi. E of SR R35 · Structure no. 000000000026800

Built
1958
67 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
108 ft
3 main spans
Daily traffic
5,200
2022 count
Owner
State
State Highway Agency

About this bridge

US 18 over West Fork Iowa River is a prestressed concrete stringer/multi-beam or girder carrying US 18 over West Fork Iowa River in Hancock 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 5,200 vehicles a day, roughly 15% of them trucks, projected to reach 5,200 by 2042. The structure is 108 ft (32.9 m) long and 36 ft wide. If it were closed, the detour would be 5 mi (8 km).

CarriesUS 18
CrossesWest Fork Iowa River
Location2.8 Mi. E of SR R35
RouteU.S. Route 18
StateIowa
Coordinates43.10425, -93.74743
Functional classRural Principal Arterial - Other

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure7 GoodSome minor problems.
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 inspectionAugust 2024
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 geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating74 US tons
Inventory rating44 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length108 ft (32.9 m)
Longest span44 ft (13.4 m)
Deck width36 ft (11 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,200 (2022)
Projected traffic5,200 by 2042
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemYes

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 US 18 over West Fork Iowa River built?

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

What condition is US 18 over West Fork Iowa 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 2024.

How much traffic does US 18 over West Fork Iowa River carry?

About 5,200 vehicles per day (2022 count), of which roughly 15% are trucks.

How long is US 18 over West Fork Iowa River?

The structure is 108 ft (32.9 m) long with a longest span of 44 ft (13.4 m) and a deck 36 ft wide.

Who owns US 18 over West Fork Iowa River?

It is owned by the State Highway Agency.