US Bridges

SB NW 100th ST over Walnut Creek

Fair

Polk County, Iowa · 079253400 · Structure no. 000000000504110

Built
1988
37 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
251 ft
3 main spans
Daily traffic
3,203
2021 count
Owner
City
City or Municipal Highway Agency

About this bridge

SB NW 100th ST over Walnut Creek is a prestressed concrete stringer/multi-beam or girder carrying SB NW 100th ST over Walnut Creek in Polk County, Iowa. It was built in 1988, so it is 37 years old, younger 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 3,203 vehicles a day, projected to reach 3,203 by 2043. The structure is 251 ft (76.5 m) long and 33 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesSB NW 100th ST
CrossesWalnut Creek
Location079253400
RouteCity Street 0
CountyPolk County
StateIowa
Coordinates41.61011, -93.7557
Functional classUrban Minor 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating71.2 US tons
Inventory rating42.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length251 ft (76.5 m)
Longest span87 ft (26.4 m)
Deck width33 ft (10.1 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,203 (2021)
Projected traffic3,203 by 2043
Trucks0%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was SB NW 100th ST over Walnut Creek built?

It was built in 1988, making it 37 years old in 2025.

What condition is SB NW 100th 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 SB NW 100th ST over Walnut Creek carry?

About 3,203 vehicles per day (2021 count).

How long is SB NW 100th ST over Walnut Creek?

The structure is 251 ft (76.5 m) long with a longest span of 87 ft (26.4 m) and a deck 33 ft wide.

Who owns SB NW 100th ST over Walnut Creek?

It is owned by the City or Municipal Highway Agency.