US Bridges

US 93 over Salmon River;carmen Br.

Fair

Lemhi County, Idaho · 4.5 N. Salmon · Structure no. 000000000017890

Built
1970
55 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
283 ft
3 main spans
Daily traffic
2,100
2023 count
Owner
State
State Highway Agency

About this bridge

US 93 over Salmon River;carmen Br. is a steel continuous stringer/multi-beam or girder carrying US 93 over Salmon River;carmen Br. in Lemhi County, Idaho. It was built in 1970, so it is 55 years old, older 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 2,100 vehicles a day, roughly 12% of them trucks, projected to reach 3,150 by 2042. The structure is 283 ft (86.3 m) long and 40 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesUS 93
CrossesSalmon River;carmen Br.
Location4.5 N. Salmon
RouteU.S. Route 93
CountyLemhi County
StateIdaho
Coordinates45.23019, -113.89439
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to 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 rating56 US tons
Inventory rating33 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length283 ft (86.3 m)
Longest span110 ft (33.5 m)
Deck width40 ft (12.2 m)
Roadway width36 ft (11.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,100 (2023)
Projected traffic3,150 by 2042
Trucks12%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$3.4 million (2018 estimate)
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was US 93 over Salmon River;carmen Br. built?

It was built in 1970, making it 55 years old in 2025.

What condition is US 93 over Salmon River;carmen 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 October 2024.

How much traffic does US 93 over Salmon River;carmen Br. carry?

About 2,100 vehicles per day (2023 count), of which roughly 12% are trucks.

How long is US 93 over Salmon River;carmen Br.?

The structure is 283 ft (86.3 m) long with a longest span of 110 ft (33.5 m) and a deck 40 ft wide.

Who owns US 93 over Salmon River;carmen Br.?

It is owned by the State Highway Agency.