US Bridges

Stc 3800;CARBARTON over N.Fk.Payette River

Good

Valley County, Idaho · 6.8 S. 0.5 E. Cascade · Structure no. 000000000028620

Built
1977
48 years old
Condition
Good
inspected August 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
322 ft
4 main spans
Daily traffic
330
2023 count
Owner
County
County Highway Agency

About this bridge

Stc 3800;CARBARTON over N.Fk.Payette River is a prestressed concrete stringer/multi-beam or girder carrying Stc 3800;CARBARTON over N.Fk.Payette River in Valley County, Idaho. It was built in 1977, so it is 48 years old, older than the Idaho average of 45.3 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 330 vehicles a day, roughly 10% of them trucks, projected to reach 495 by 2042. The structure is 322 ft (98.1 m) long and 29 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

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CarriesStc 3800;CARBARTON
CrossesN.Fk.Payette River
Location6.8 S. 0.5 E. Cascade
RouteCounty Highway 3800
CountyValley County
StateIdaho
Coordinates44.41383, -116.03164
Functional classRural Major Collector

Condition and inspection

Good

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation7: Better than 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 alignment6: Equal to present minimum criteria
Operating rating65 US tons
Inventory rating37 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length322 ft (98.1 m)
Longest span79 ft (24.1 m)
Deck width29 ft (8.7 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic330 (2023)
Projected traffic495 by 2042
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Stc 3800;CARBARTON over N.Fk.Payette River built?

It was built in 1977, making it 48 years old in 2025.

What condition is Stc 3800;CARBARTON over N.Fk.Payette River 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 August 2023.

How much traffic does Stc 3800;CARBARTON over N.Fk.Payette River carry?

About 330 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is Stc 3800;CARBARTON over N.Fk.Payette River?

The structure is 322 ft (98.1 m) long with a longest span of 79 ft (24.1 m) and a deck 29 ft wide.

Who owns Stc 3800;CARBARTON over N.Fk.Payette River?

It is owned by the County Highway Agency.