US Bridges

I 15 Nbl over Stc 1758;UPRR;INKOM Op

Fair

Bannock County, Idaho · 1.3 S. Inkom · Structure no. 000000000011145

Built
1963
62 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
389 ft
6 main spans
Daily traffic
8,000
2023 count
Owner
State
State Highway Agency

About this bridge

I 15 Nbl over Stc 1758;UPRR;INKOM Op is a prestressed concrete stringer/multi-beam or girder carrying I 15 Nbl over Stc 1758;UPRR;INKOM Op in Bannock County, Idaho. It was built in 1963, so it is 62 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 8,000 vehicles a day, roughly 23% of them trucks, projected to reach 12,000 by 2042. The structure is 389 ft (118.6 m) long and 35 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 15 Nbl
CrossesStc 1758;UPRR;INKOM Op
Location1.3 S. Inkom
RouteInterstate 15
CountyBannock County
StateIdaho
Coordinates42.78611, -112.23317
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating63.1 US tons
Inventory rating35.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20
Structure length389 ft (118.6 m)
Longest span87 ft (26.5 m)
Deck width35 ft (10.6 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,000 (2023)
Projected traffic12,000 by 2042
Trucks23%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and railroad
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$4.4 million (2019 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 15 Nbl over Stc 1758;UPRR;INKOM Op built?

It was built in 1963, making it 62 years old in 2025.

What condition is I 15 Nbl over Stc 1758;UPRR;INKOM Op 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 June 2023.

How much traffic does I 15 Nbl over Stc 1758;UPRR;INKOM Op carry?

About 8,000 vehicles per day (2023 count), of which roughly 23% are trucks.

How long is I 15 Nbl over Stc 1758;UPRR;INKOM Op?

The structure is 389 ft (118.6 m) long with a longest span of 87 ft (26.5 m) and a deck 35 ft wide.

Who owns I 15 Nbl over Stc 1758;UPRR;INKOM Op?

It is owned by the State Highway Agency.