US Bridges

320th ST over Wharam Creek

FairPosted for load

Cerro Gordo County, Iowa · 097201801 · Structure no. 000000000106710

Built
1914
111 years old
Condition
Fair
inspected January 2024
Type
Slab
Concrete
Length
23 ft
1 main span
Daily traffic
21
2022 count
Owner
County
County Highway Agency

About this bridge

320th ST over Wharam Creek is a concrete slab carrying 320th ST over Wharam Creek in Cerro Gordo County, Iowa. It was built in 1914, so it is 111 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. Its operating status is: posted for load restriction.

It carries about 21 vehicles a day, projected to reach 21 by 2044. The structure is 23 ft (7 m) long and 22 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
Carries320th ST
CrossesWharam Creek
Location097201801
RouteCounty Highway 0
CountyCerro Gordo County
StateIowa
Coordinates43.22758, -93.25742
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJanuary 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating34.7 US tons
Inventory rating18.8 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length23 ft (7 m)
Longest span22 ft (6.7 m)
Deck width22 ft (6.8 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic21 (2022)
Projected traffic21 by 2044
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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 320th ST over Wharam Creek built?

It was built in 1914, making it 111 years old in 2025.

What condition is 320th ST over Wharam 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 January 2024.

How much traffic does 320th ST over Wharam Creek carry?

About 21 vehicles per day (2022 count).

How long is 320th ST over Wharam Creek?

The structure is 23 ft (7 m) long with a longest span of 22 ft (6.7 m) and a deck 22 ft wide.

Who owns 320th ST over Wharam Creek?

It is owned by the County Highway Agency.