US Bridges

I-15 (SR-15) over Black Slough

Fair

Box Elder County, Utah · West of Brigham City · Structure no. 0E1349

Built
1965
60 years old
Condition
Fair
inspected May 2023
Type
Culvert
Concrete Continuous
Length
22 ft
2 main spans
Daily traffic
—
2023 count
Owner
State
State Highway Agency

About this bridge

I-15 (SR-15) over Black Slough is a concrete continuous culvert carrying I-15 (SR-15) over Black Slough in Box Elder County, Utah. It was built in 1965, so it is 60 years old, older than the Utah average of 40.1 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.

No traffic count is recorded. The structure is 22 ft (6.7 m) long. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesI-15 (SR-15)
CrossesBlack Slough
LocationWest of Brigham City
RouteInterstate 15
CountyBox Elder County
StateUtah
Coordinates41.52486, -112.06447
Functional classUrban 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
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating22.8 US tons
Inventory rating14.3 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadHS 20 + Mod
Structure length22 ft (6.7 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deck99 ft (30.2 m)

Traffic and service

Average daily traffic—
Projected traffic—
Trucks31%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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 statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-15 (SR-15) over Black Slough built?

It was built in 1965, making it 60 years old in 2025.

What condition is I-15 (SR-15) over Black Slough 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 May 2023.

How much traffic does I-15 (SR-15) over Black Slough carry?

No traffic count is recorded for this structure.

How long is I-15 (SR-15) over Black Slough?

The structure is 22 ft (6.7 m) long with a longest span of 10 ft (3 m).

Who owns I-15 (SR-15) over Black Slough?

It is owned by the State Highway Agency.