US Bridges

320th ST over Wolf Creek

Good

Woodbury County, Iowa · 086452701 · Structure no. 000000000351071

Built
2019
6 years old
Condition
Good
inspected June 2023
Type
Slab
Concrete Continuous
Length
123 ft
3 main spans
Daily traffic
5
2022 count
Owner
County
County Highway Agency

About this bridge

320th ST over Wolf Creek is a concrete continuous slab carrying 320th ST over Wolf Creek in Woodbury County, Iowa. It was built in 2019, so it is 6 years old, younger than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 5 vehicles a day, projected to reach 5 by 2043. The structure is 123 ft (37.5 m) long and 27 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
Carries320th ST
CrossesWolf Creek
Location086452701
RouteCounty Highway 0
CountyWoodbury County
StateIowa
Coordinates42.24128, -96.05927
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating46.4 US tons
Inventory rating35.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length123 ft (37.5 m)
Longest span47 ft (14.3 m)
Deck width27 ft (8.3 m)
Roadway width25 ft (7.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5 (2022)
Projected traffic5 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost$30,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was 320th ST over Wolf Creek built?

It was built in 2019, making it 6 years old in 2025.

What condition is 320th ST over Wolf Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in June 2023.

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

About 5 vehicles per day (2022 count).

How long is 320th ST over Wolf Creek?

The structure is 123 ft (37.5 m) long with a longest span of 47 ft (14.3 m) and a deck 27 ft wide.

Who owns 320th ST over Wolf Creek?

It is owned by the County Highway Agency.