US Bridges

SH 55 over N. Fk. Payette River

Good

Valley County, Idaho · Cascade Ncl · Structure no. 000000000014831

Built
2015
10 years old
Condition
Good
inspected May 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
250 ft
2 main spans
Daily traffic
5,700
2023 count
Owner
State
State Highway Agency

About this bridge

SH 55 over N. Fk. Payette River is a prestressed concrete stringer/multi-beam or girder carrying SH 55 over N. Fk. Payette River in Valley County, Idaho. It was built in 2015, so it is 10 years old, younger 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 5,700 vehicles a day, roughly 30% of them trucks, projected to reach 8,550 by 2042. The structure is 250 ft (76.2 m) long and 53 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesSH 55
CrossesN. Fk. Payette River
LocationCascade Ncl
RouteState Highway 55
CountyValley County
StateIdaho
Coordinates44.52397, -116.04467
Functional classRural Principal Arterial - Other

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.
Substructure7 GoodSome minor problems.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionMay 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating61.4 US tons
Inventory rating40.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans2
Design loadHL 93
Structure length250 ft (76.2 m)
Longest span123 ft (37.5 m)
Deck width53 ft (16.3 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,700 (2023)
Projected traffic8,550 by 2042
Trucks30%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 SH 55 over N. Fk. Payette River built?

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

What condition is SH 55 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 May 2023.

How much traffic does SH 55 over N. Fk. Payette River carry?

About 5,700 vehicles per day (2023 count), of which roughly 30% are trucks.

How long is SH 55 over N. Fk. Payette River?

The structure is 250 ft (76.2 m) long with a longest span of 123 ft (37.5 m) and a deck 53 ft wide.

Who owns SH 55 over N. Fk. Payette River?

It is owned by the State Highway Agency.