US Bridges

I-35 over Willow Creek

Fair

Cerro Gordo County, Iowa · 0.2 Miles S of N Jct. 18 · Structure no. 000000000019220

Built
1971
54 years old
Condition
Fair
inspected August 2023
Type
Culvert
Concrete Continuous
Length
28 ft
2 main spans
Daily traffic
17,200
2023 count
Owner
State
State Highway Agency

About this bridge

I-35 over Willow Creek is a concrete continuous culvert carrying I-35 over Willow Creek in Cerro Gordo County, Iowa. It was built in 1971, so it is 54 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 17,200 vehicles a day, roughly 33% of them trucks, projected to reach 17,200 by 2043. The structure is 28 ft (8.5 m) long. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI-35
CrossesWillow Creek
Location0.2 Miles S of N Jct. 18
RouteInterstate 35
CountyCerro Gordo County
StateIowa
Coordinates43.14347, -93.35571
Functional classUrban Principal Arterial - Interstate

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 inspectionAugust 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
Waterway adequacy8: Equal to present desirable 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 length28 ft (8.5 m)
Longest span12 ft (3.7 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic17,200 (2023)
Projected traffic17,200 by 2043
Trucks33%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 I-35 over Willow Creek built?

It was built in 1971, making it 54 years old in 2025.

What condition is I-35 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 August 2023.

How much traffic does I-35 over Willow Creek carry?

About 17,200 vehicles per day (2023 count), of which roughly 33% are trucks.

How long is I-35 over Willow Creek?

The structure is 28 ft (8.5 m) long with a longest span of 12 ft (3.7 m).

Who owns I-35 over Willow Creek?

It is owned by the State Highway Agency.