US Bridges

SH 48 over Snake River;roberts Br.

Fair

Jefferson County, Idaho · 2.0 E. Roberts · Structure no. 000000000014440

Built
1978
47 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
414 ft
4 main spans
Daily traffic
2,000
2023 count
Owner
State
State Highway Agency

About this bridge

SH 48 over Snake River;roberts Br. is a prestressed concrete stringer/multi-beam or girder carrying SH 48 over Snake River;roberts Br. in Jefferson County, Idaho. It was built in 1978, so it is 47 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 5 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 2,000 vehicles a day, roughly 16% of them trucks, projected to reach 3,000 by 2042. The structure is 414 ft (126.2 m) long and 40 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesSH 48
CrossesSnake River;roberts Br.
Location2.0 E. Roberts
RouteState Highway 48
CountyJefferson County
StateIdaho
Coordinates43.72283, -112.08675
Functional classRural Major Collector

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating69 US tons
Inventory rating33 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length414 ft (126.2 m)
Longest span102 ft (31.1 m)
Deck width40 ft (12.1 m)
Roadway width37 ft (11.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,000 (2023)
Projected traffic3,000 by 2042
Trucks16%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 km)
TollOn a free road
National Highway SystemNo

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 48 over Snake River;roberts Br. built?

It was built in 1978, making it 47 years old in 2025.

What condition is SH 48 over Snake River;roberts 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 July 2023.

How much traffic does SH 48 over Snake River;roberts Br. carry?

About 2,000 vehicles per day (2023 count), of which roughly 16% are trucks.

How long is SH 48 over Snake River;roberts Br.?

The structure is 414 ft (126.2 m) long with a longest span of 102 ft (31.1 m) and a deck 40 ft wide.

Who owns SH 48 over Snake River;roberts Br.?

It is owned by the State Highway Agency.