US Bridges

320th ST over Stream

Good

Woodbury County, Iowa · 086432703 · Structure no. 000000000350641

Built
2004
21 years old
Condition
Good
inspected June 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
84 ft
1 main span
Daily traffic
11
2022 count
Owner
County
County Highway Agency

About this bridge

320th ST over Stream is a steel stringer/multi-beam or girder carrying 320th ST over Stream in Woodbury County, Iowa. It was built in 2004, so it is 21 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 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 11 vehicles a day, projected to reach 11 by 2043. The structure is 84 ft (25.6 m) long and 24 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
Carries320th ST
CrossesStream
Location086432703
RouteCounty Highway 0
CountyWoodbury County
StateIowa
Coordinates42.24051, -95.82623
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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating46.6 US tons
Inventory rating29 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckWood or timber
Main spans1 (+2 approach)
Design loadHS 20
Structure length84 ft (25.6 m)
Longest span37 ft (11.3 m)
Deck width24 ft (7.3 m)
Roadway width24 ft (7.2 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 closed1.9 mi (3 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 Stream built?

It was built in 2004, making it 21 years old in 2025.

What condition is 320th ST over Stream 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 Stream carry?

About 11 vehicles per day (2022 count).

How long is 320th ST over Stream?

The structure is 84 ft (25.6 m) long with a longest span of 37 ft (11.3 m) and a deck 24 ft wide.

Who owns 320th ST over Stream?

It is owned by the County Highway Agency.