US Bridges

I-15 (SR-15) Sbl over Malad River

Fair

Box Elder County, Utah · 1.5 Mi.So.Plymouth Int. · Structure no. 3C 764

Built
1990
35 years old
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
497 ft
3 main spans
Daily traffic
13,856
2023 count
Owner
State
State Highway Agency

About this bridge

I-15 (SR-15) Sbl over Malad River is a steel continuous stringer/multi-beam or girder carrying I-15 (SR-15) Sbl over Malad River in Box Elder County, Utah. It was built in 1990, so it is 35 years old, younger 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.

It carries about 13,856 vehicles a day, roughly 41% of them trucks, projected to reach 16,627 by 2043. The structure is 497 ft (151.4 m) long and 45 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-15 (SR-15) Sbl
CrossesMalad River
Location1.5 Mi.So.Plymouth Int.
RouteInterstate 15
CountyBox Elder County
StateUtah
Coordinates41.86592, -112.1699
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry8: Equal to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating58.5 US tons
Inventory rating31.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length497 ft (151.4 m)
Longest span200 ft (61 m)
Deck width45 ft (13.8 m)
Roadway width42 ft (12.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic13,856 (2023)
Projected traffic16,627 by 2043
Trucks41%
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 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) Sbl over Malad River built?

It was built in 1990, making it 35 years old in 2025.

What condition is I-15 (SR-15) Sbl over Malad River 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 April 2023.

How much traffic does I-15 (SR-15) Sbl over Malad River carry?

About 13,856 vehicles per day (2023 count), of which roughly 41% are trucks.

How long is I-15 (SR-15) Sbl over Malad River?

The structure is 497 ft (151.4 m) long with a longest span of 200 ft (61 m) and a deck 45 ft wide.

Who owns I-15 (SR-15) Sbl over Malad River?

It is owned by the State Highway Agency.