US Bridges

NW 86th ST over Big Creek Tributary

Fair

Polk County, Iowa · 081251402 · Structure no. 000000000283160

Built
1931
94 years old
Condition
Fair
inspected April 2023
Type
Culvert
Concrete Continuous
Length
20 ft
2 main spans
Daily traffic
264
2022 count
Owner
County
County Highway Agency

About this bridge

NW 86th ST over Big Creek Tributary is a concrete continuous culvert carrying NW 86th ST over Big Creek Tributary in Polk County, Iowa. It was built in 1931, so it is 94 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 264 vehicles a day, roughly 11% of them trucks, projected to reach 264 by 2042. The structure is 20 ft (6.1 m) long. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesNW 86th ST
CrossesBig Creek Tributary
Location081251402
RouteCounty Highway 0
CountyPolk County
StateIowa
Coordinates41.82818, -93.7366
Functional classRural Major 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
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 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 adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating20.2 US tons
Inventory rating15 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadUnknown
Structure length20 ft (6.1 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic264 (2022)
Projected traffic264 by 2042
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was NW 86th ST over Big Creek Tributary built?

It was built in 1931, making it 94 years old in 2025.

What condition is NW 86th ST over Big Creek Tributary 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 2023.

How much traffic does NW 86th ST over Big Creek Tributary carry?

About 264 vehicles per day (2022 count), of which roughly 11% are trucks.

How long is NW 86th ST over Big Creek Tributary?

The structure is 20 ft (6.1 m) long with a longest span of 10 ft (3 m).

Who owns NW 86th ST over Big Creek Tributary?

It is owned by the County Highway Agency.