US Bridges

I 15 Nbl over I 15B;W.INKOM Ic

Poor

Bannock County, Idaho · 0.5 W. Inkom · Structure no. 000000000011185

Built
1962
63 years old
Condition
Poor
inspected September 2024
Type
Stringer/Multi-beam or Girder
Concrete
Length
114 ft
3 main spans
Daily traffic
7,750
2023 count
Owner
State
State Highway Agency

About this bridge

I 15 Nbl over I 15B;W.INKOM Ic is a concrete stringer/multi-beam or girder carrying I 15 Nbl over I 15B;W.INKOM Ic in Bannock County, Idaho. It was built in 1962, so it is 63 years old, older than the Idaho average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 7,750 vehicles a day, roughly 24% of them trucks, projected to reach 11,625 by 2042. The structure is 114 ft (34.7 m) long and 40 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 15 Nbl
CrossesI 15B;W.INKOM Ic
Location0.5 W. Inkom
RouteInterstate 15
CountyBannock County
StateIdaho
Coordinates42.7989, -112.26149
Functional classRural Principal Arterial - Interstate

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionSeptember 2024
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating56 US tons
Inventory rating34 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length114 ft (34.7 m)
Longest span37 ft (11.3 m)
Deck width40 ft (12.2 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,750 (2023)
Projected traffic11,625 by 2042
Trucks24%
Lanes on structure2
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
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$1.5 million (2019 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 15 Nbl over I 15B;W.INKOM Ic built?

It was built in 1962, making it 63 years old in 2025.

What condition is I 15 Nbl over I 15B;W.INKOM Ic in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in September 2024.

How much traffic does I 15 Nbl over I 15B;W.INKOM Ic carry?

About 7,750 vehicles per day (2023 count), of which roughly 24% are trucks.

How long is I 15 Nbl over I 15B;W.INKOM Ic?

The structure is 114 ft (34.7 m) long with a longest span of 37 ft (11.3 m) and a deck 40 ft wide.

Who owns I 15 Nbl over I 15B;W.INKOM Ic?

It is owned by the State Highway Agency.