US Bridges

SH 55 over Lake Fork Creek

Fair

Valley County, Idaho · 2.9 S. Lake Fork · Structure no. 000000000014865

Built
1985
40 years old
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
95 ft
1 main span
Daily traffic
6,500
2023 count
Owner
State
State Highway Agency

About this bridge

SH 55 over Lake Fork Creek is a prestressed concrete stringer/multi-beam or girder carrying SH 55 over Lake Fork Creek in Valley County, Idaho. It was built in 1985, so it is 40 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 6,500 vehicles a day, roughly 11% of them trucks, projected to reach 9,750 by 2042. The structure is 95 ft (29 m) long and 46 ft wide. If it were closed, the detour would be 8.7 mi (14 km).

Location

Open in Google Maps
CarriesSH 55
CrossesLake Fork Creek
Location2.9 S. Lake Fork
RouteState Highway 55
CountyValley County
StateIdaho
Coordinates44.78872, -116.07719
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 protection8 Very GoodNo problems noted.
Last inspectionMay 2024
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 adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating89.9 US tons
Inventory rating55 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length95 ft (29 m)
Longest span93 ft (28.2 m)
Deck width46 ft (13.9 m)
Roadway width43 ft (13 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,500 (2023)
Projected traffic9,750 by 2042
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.7 mi (14 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 Lake Fork Creek built?

It was built in 1985, making it 40 years old in 2025.

What condition is SH 55 over Lake Fork Creek 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 2024.

How much traffic does SH 55 over Lake Fork Creek carry?

About 6,500 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is SH 55 over Lake Fork Creek?

The structure is 95 ft (29 m) long with a longest span of 93 ft (28.2 m) and a deck 46 ft wide.

Who owns SH 55 over Lake Fork Creek?

It is owned by the State Highway Agency.