US Bridges

NW 100th ST over Big Creek Tributary

Fair

Polk County, Iowa · 081250302 · Structure no. 000000000283015

Built
1975
50 years old
Condition
Fair
inspected May 2023
Type
Culvert
Concrete Continuous
Length
22 ft
2 main spans
Daily traffic
71
2022 count
Owner
County
County Highway Agency

About this bridge

NW 100th ST over Big Creek Tributary is a concrete continuous culvert carrying NW 100th ST over Big Creek Tributary in Polk County, Iowa. It was built in 1975, so it is 50 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 71 vehicles a day, projected to reach 71 by 2042. The structure is 22 ft (6.7 m) long. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesNW 100th ST
CrossesBig Creek Tributary
Location081250302
RouteCounty Highway 0
CountyPolk County
StateIowa
Coordinates41.85484, -93.75644
Functional classRural Local

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 protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 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
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating40.2 US tons
Inventory rating24.1 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadH 20
Structure length22 ft (6.7 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 traffic71 (2022)
Projected traffic71 by 2042
Trucks0%
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 statusNot eligible for the National Register of Historic Places
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 100th ST over Big Creek Tributary built?

It was built in 1975, making it 50 years old in 2025.

What condition is NW 100th 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 May 2023.

How much traffic does NW 100th ST over Big Creek Tributary carry?

About 71 vehicles per day (2022 count).

How long is NW 100th ST over Big Creek Tributary?

The structure is 22 ft (6.7 m) long with a longest span of 10 ft (3 m).

Who owns NW 100th ST over Big Creek Tributary?

It is owned by the County Highway Agency.