US Bridges

FM 310th ST over Stream

FairPosted for load

Johnson County, Iowa · 080052503 · Structure no. 000000000204790

Built
1900
125 years old
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
20 ft
1 main span
Daily traffic
60
2021 count
Owner
County
County Highway Agency

About this bridge

FM 310th ST over Stream is a wood or timber stringer/multi-beam or girder carrying FM 310th ST over Stream in Johnson County, Iowa. It was built in 1900, so it is 125 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 5 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 60 vehicles a day, projected to reach 60 by 2043. The structure is 20 ft (6.1 m) long and 20 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesFM 310th ST
CrossesStream
Location080052503
RouteCounty Highway 0
CountyJohnson County
StateIowa
Coordinates41.70739, -91.3725
Functional classRural Minor Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 2023
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 rating22.8 US tons
Inventory rating18.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20
Structure length20 ft (6.1 m)
Longest span20 ft (6.1 m)
Deck width20 ft (6.1 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic60 (2021)
Projected traffic60 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM 310th ST over Stream built?

It was built in 1900, making it 125 years old in 2025.

What condition is FM 310th ST over Stream 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 April 2023.

How much traffic does FM 310th ST over Stream carry?

About 60 vehicles per day (2021 count).

How long is FM 310th ST over Stream?

The structure is 20 ft (6.1 m) long with a longest span of 20 ft (6.1 m) and a deck 20 ft wide.

Who owns FM 310th ST over Stream?

It is owned by the County Highway Agency.