US Bridges

320th ST over Stram

Good

Guthrie County, Iowa · 078331901 · Structure no. 000000000366160

Built
2015
10 years old
Condition
Good
inspected November 2021
Type
Channel Beam
Concrete
Length
46 ft
1 main span
Daily traffic
11
2022 count
Owner
County
County Highway Agency

About this bridge

320th ST over Stram is a concrete channel beam carrying 320th ST over Stram in Guthrie County, Iowa. It was built in 2015, so it is 10 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 11 vehicles a day, projected to reach 11 by 2041. The structure is 46 ft (14 m) long and 31 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
Carries320th ST
CrossesStram
Location078331901
RouteCounty Highway 0
CountyGuthrie County
StateIowa
Coordinates41.54738, -94.69907
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 protection7 GoodSome minor problems.
Last inspectionNovember 2021
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating61 US tons
Inventory rating36 US tons

Structure

Structure typeChannel Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length46 ft (14 m)
Longest span45 ft (13.7 m)
Deck width31 ft (9.5 m)
Roadway width31 ft (9.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11 (2022)
Projected traffic11 by 2041
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 statusNot eligible for the National Register of Historic Places
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 320th ST over Stram built?

It was built in 2015, making it 10 years old in 2025.

What condition is 320th ST over Stram 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 November 2021.

How much traffic does 320th ST over Stram carry?

About 11 vehicles per day (2022 count).

How long is 320th ST over Stram?

The structure is 46 ft (14 m) long with a longest span of 45 ft (13.7 m) and a deck 31 ft wide.

Who owns 320th ST over Stram?

It is owned by the County Highway Agency.