US Bridges

US 18 over Willow Creek

Fair

Cerro Gordo County, Iowa · 0.3 Mi. W of Jct. I-35 · Structure no. 000000000018740

Built
1952
73 years old, rebuilt 1969
Condition
Fair
inspected April 2024
Type
Culvert
Concrete Continuous
Length
35 ft
2 main spans
Daily traffic
14,400
2022 count
Owner
State
State Highway Agency

About this bridge

US 18 over Willow Creek is a concrete continuous culvert carrying US 18 over Willow Creek in Cerro Gordo County, Iowa. It was built in 1952 and reconstructed in 1969, so it is 73 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 6 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 14,400 vehicles a day, roughly 5% of them trucks, projected to reach 14,400 by 2044. The structure is 35 ft (10.7 m) long. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesUS 18
CrossesWillow Creek
Location0.3 Mi. W of Jct. I-35
RouteU.S. Route 18
CountyCerro Gordo County
StateIowa
Coordinates43.14519, -93.3618
Functional classUrban Other Principal 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
Channel and channel protection7 GoodSome minor problems.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2024
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
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating27 US tons
Inventory rating20 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadH 20
Structure length35 ft (10.7 m)
Longest span17 ft (5.2 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic14,400 (2022)
Projected traffic14,400 by 2044
Trucks5%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 Willow Creek built?

It was built in 1952, making it 73 years old in 2025. It was reconstructed in 1969.

What condition is US 18 over Willow Creek 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 April 2024.

How much traffic does US 18 over Willow Creek carry?

About 14,400 vehicles per day (2022 count), of which roughly 5% are trucks.

How long is US 18 over Willow Creek?

The structure is 35 ft (10.7 m) long with a longest span of 17 ft (5.2 m).

Who owns US 18 over Willow Creek?

It is owned by the State Highway Agency.