US Bridges

FM 170th Ave over Willow Creek

Fair

Clay County, Iowa · 095373202 · Structure no. 000000000116360

Built
1963
62 years old
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
71 ft
1 main span
Daily traffic
219
2022 count
Owner
County
County Highway Agency

About this bridge

FM 170th Ave over Willow Creek is a steel stringer/multi-beam or girder carrying FM 170th Ave over Willow Creek in Clay County, Iowa. It was built in 1963, so it is 62 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 219 vehicles a day, roughly 17% of them trucks, projected to reach 219 by 2043. The structure is 71 ft (21.6 m) long and 30 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesFM 170th Ave
CrossesWillow Creek
Location095373202
RouteCounty Highway 0
CountyClay County
StateIowa
Coordinates43.00084, -95.25028
Functional classRural Minor Collector

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMarch 2023
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 geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating47.2 US tons
Inventory rating38.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length71 ft (21.6 m)
Longest span68 ft (20.7 m)
Deck width30 ft (9.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic219 (2022)
Projected traffic219 by 2043
Trucks17%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM 170th Ave over Willow Creek built?

It was built in 1963, making it 62 years old in 2025.

What condition is FM 170th Ave 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 March 2023.

How much traffic does FM 170th Ave over Willow Creek carry?

About 219 vehicles per day (2022 count), of which roughly 17% are trucks.

How long is FM 170th Ave over Willow Creek?

The structure is 71 ft (21.6 m) long with a longest span of 68 ft (20.7 m) and a deck 30 ft wide.

Who owns FM 170th Ave over Willow Creek?

It is owned by the County Highway Agency.