US Bridges

I 15 Nbl over Butte Market Lake Canal

Fair

Jefferson County, Idaho · 4.6 S. Roberts · Structure no. 000000000011810

Built
1968
57 years old
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Concrete
Length
42 ft
1 main span
Daily traffic
3,050
2023 count
Owner
State
State Highway Agency

About this bridge

I 15 Nbl over Butte Market Lake Canal is a concrete stringer/multi-beam or girder carrying I 15 Nbl over Butte Market Lake Canal in Jefferson County, Idaho. It was built in 1968, so it is 57 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 3,050 vehicles a day, roughly 31% of them trucks, projected to reach 4,575 by 2042. The structure is 42 ft (12.8 m) long and 41 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 15 Nbl
CrossesButte Market Lake Canal
Location4.6 S. Roberts
RouteInterstate 15
CountyJefferson County
StateIdaho
Coordinates43.65474, -112.1022
Functional classRural Principal Arterial - Interstate

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
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 rating57 US tons
Inventory rating34 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length42 ft (12.8 m)
Longest span41 ft (12.5 m)
Deck width41 ft (12.4 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,050 (2023)
Projected traffic4,575 by 2042
Trucks31%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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$656,000 (2021 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I 15 Nbl over Butte Market Lake Canal built?

It was built in 1968, making it 57 years old in 2025.

What condition is I 15 Nbl over Butte Market Lake Canal 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 2023.

How much traffic does I 15 Nbl over Butte Market Lake Canal carry?

About 3,050 vehicles per day (2023 count), of which roughly 31% are trucks.

How long is I 15 Nbl over Butte Market Lake Canal?

The structure is 42 ft (12.8 m) long with a longest span of 41 ft (12.5 m) and a deck 41 ft wide.

Who owns I 15 Nbl over Butte Market Lake Canal?

It is owned by the State Highway Agency.