US Bridges

SH 55 over N. Fk. Payette River

Fair

Valley County, Idaho · Cascade SE City Limits · Structure no. 000000000014826

Built
2013
12 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
393 ft
3 main spans
Daily traffic
7,800
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 2013, so it is 12 years old, younger than the Idaho average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 7,800 vehicles a day, roughly 7% of them trucks, projected to reach 11,700 by 2042. The structure is 393 ft (119.8 m) long and 61 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSH 55
CrossesN. Fk. Payette River
LocationCascade SE City Limits
RouteState Highway 55
CountyValley County
StateIdaho
Coordinates44.50017, -116.02308
Functional classRural Principal Arterial - Other

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
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 geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating65 US tons
Inventory rating42.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length393 ft (119.8 m)
Longest span129 ft (39.3 m)
Deck width61 ft (18.7 m)
Roadway width60 ft (18.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,800 (2023)
Projected traffic11,700 by 2042
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 2013, making it 12 years old in 2025.

What condition is SH 55 over N. Fk. Payette River 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 May 2023.

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

About 7,800 vehicles per day (2023 count), of which roughly 7% are trucks.

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

The structure is 393 ft (119.8 m) long with a longest span of 129 ft (39.3 m) and a deck 61 ft wide.

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

It is owned by the State Highway Agency.