US Bridges

NW 86th ST over Walnut Creek

Fair

Polk County, Iowa · 079253502 · Structure no. 000000000002411

Built
1970
55 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
166 ft
3 main spans
Daily traffic
24,581
2021 count
Owner
City
City or Municipal Highway Agency

About this bridge

NW 86th ST over Walnut Creek is a prestressed concrete stringer/multi-beam or girder carrying NW 86th ST over Walnut Creek in Polk County, Iowa. It was built in 1970, so it is 55 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 24,581 vehicles a day, projected to reach 24,581 by 2043. The structure is 166 ft (50.7 m) long and 57 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesNW 86th ST
CrossesWalnut Creek
Location079253502
RouteCity Street 0
CountyPolk County
StateIowa
Coordinates41.60202, -93.73619
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating56.3 US tons
Inventory rating33.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length166 ft (50.7 m)
Longest span69 ft (21 m)
Deck width57 ft (17.4 m)
Roadway width48 ft (14.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic24,581 (2021)
Projected traffic24,581 by 2043
Trucks0%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$628,000
NavigationNo navigation control on waterway

Frequently asked questions

When was NW 86th ST over Walnut Creek built?

It was built in 1970, making it 55 years old in 2025.

What condition is NW 86th ST over Walnut 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 May 2023.

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

About 24,581 vehicles per day (2021 count).

How long is NW 86th ST over Walnut Creek?

The structure is 166 ft (50.7 m) long with a longest span of 69 ft (21 m) and a deck 57 ft wide.

Who owns NW 86th ST over Walnut Creek?

It is owned by the City or Municipal Highway Agency.