US Bridges

420th ST over Elk Creek

Fair

Clay County, Iowa · 095352001 · Structure no. 000000000116091

Built
1978
47 years old
Condition
Fair
inspected March 2023
Type
Culvert
Concrete Continuous
Length
54 ft
3 main spans
Daily traffic
11
2022 count
Owner
County
County Highway Agency

About this bridge

420th ST over Elk Creek is a concrete continuous culvert carrying 420th ST over Elk Creek in Clay County, Iowa. It was built in 1978, so it is 47 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 11 vehicles a day, projected to reach 11 by 2043. The structure is 54 ft (16.5 m) long. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
Carries420th ST
CrossesElk Creek
Location095352001
RouteCounty Highway 0
CountyClay County
StateIowa
Coordinates43.03897, -95.00763
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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 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 rating42.5 US tons
Inventory rating25.4 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans3
Design loadH 20
Structure length54 ft (16.5 m)
Longest span14 ft (4.3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11 (2022)
Projected traffic11 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 420th ST over Elk Creek built?

It was built in 1978, making it 47 years old in 2025.

What condition is 420th ST over Elk 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 420th ST over Elk Creek carry?

About 11 vehicles per day (2022 count).

How long is 420th ST over Elk Creek?

The structure is 54 ft (16.5 m) long with a longest span of 14 ft (4.3 m).

Who owns 420th ST over Elk Creek?

It is owned by the County Highway Agency.