US Bridges

I 15 Sbl over Humphrey Road Ic

Fair

Clark County, Idaho · At Humphrey · Structure no. 000000000011986

Built
1991
34 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Concrete
Length
86 ft
1 main span
Daily traffic
1,750
2023 count
Owner
State
State Highway Agency

About this bridge

I 15 Sbl over Humphrey Road Ic is a concrete stringer/multi-beam or girder carrying I 15 Sbl over Humphrey Road Ic in Clark County, Idaho. It was built in 1991, so it is 34 years old, younger 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 1,750 vehicles a day, roughly 35% of them trucks, projected to reach 2,625 by 2042. The structure is 86 ft (26.2 m) long and 44 ft wide.

Location

Open in Google Maps
CarriesI 15 Sbl
CrossesHumphrey Road Ic
LocationAt Humphrey
RouteInterstate 15
CountyClark County
StateIdaho
Coordinates44.4875, -112.23542
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.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Last inspectionAugust 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation8: Equal to present desirable criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating84 US tons
Inventory rating50 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length86 ft (26.2 m)
Longest span84 ft (25.6 m)
Deck width44 ft (13.3 m)
Roadway width41 ft (12.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,750 (2023)
Projected traffic2,625 by 2042
Trucks35%
Lanes on structure2
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed—
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 proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 15 Sbl over Humphrey Road Ic built?

It was built in 1991, making it 34 years old in 2025.

What condition is I 15 Sbl over Humphrey Road Ic 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 August 2023.

How much traffic does I 15 Sbl over Humphrey Road Ic carry?

About 1,750 vehicles per day (2023 count), of which roughly 35% are trucks.

How long is I 15 Sbl over Humphrey Road Ic?

The structure is 86 ft (26.2 m) long with a longest span of 84 ft (25.6 m) and a deck 44 ft wide.

Who owns I 15 Sbl over Humphrey Road Ic?

It is owned by the State Highway Agency.