US Bridges

SH 55 over Snake River (marsing Br)

Fair

Owyhee County, Idaho · Near Marsing Ecl · Structure no. 000000000014671

Built
2020
5 years old
Condition
Fair
inspected March 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
812 ft
6 main spans
Daily traffic
7,500
2023 count
Owner
State
State Highway Agency

About this bridge

SH 55 over Snake River (marsing Br) is a prestressed concrete stringer/multi-beam or girder carrying SH 55 over Snake River (marsing Br) in Owyhee County, Idaho. It was built in 2020, so it is 5 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 7,500 vehicles a day, roughly 14% of them trucks, projected to reach 11,250 by 2042. The structure is 812 ft (247.5 m) long and 46 ft wide. If it were closed, the detour would be 14.3 mi (23 km).

Location

Open in Google Maps
CarriesSH 55
CrossesSnake River (marsing Br)
LocationNear Marsing Ecl
RouteState Highway 55
CountyOwyhee County
StateIdaho
Coordinates43.54797, -116.80136
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 protection7 GoodSome minor problems.
Last inspectionMarch 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment9: Superior to present desirable criteria
Operating rating55.3 US tons
Inventory rating40 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans6
Design loadHL 93
Structure length812 ft (247.5 m)
Longest span149 ft (45.3 m)
Deck width46 ft (14.1 m)
Roadway width36 ft (11 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,500 (2023)
Projected traffic11,250 by 2042
Trucks14%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed14.3 mi (23 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—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was SH 55 over Snake River (marsing Br) built?

It was built in 2020, making it 5 years old in 2025.

What condition is SH 55 over Snake River (marsing Br) 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 March 2024.

How much traffic does SH 55 over Snake River (marsing Br) carry?

About 7,500 vehicles per day (2023 count), of which roughly 14% are trucks.

How long is SH 55 over Snake River (marsing Br)?

The structure is 812 ft (247.5 m) long with a longest span of 149 ft (45.3 m) and a deck 46 ft wide.

Who owns SH 55 over Snake River (marsing Br)?

It is owned by the State Highway Agency.