US Bridges

I-15 (SR-15) Sbl over SR-315 to Willard Bay

Fair

Box Elder County, Utah · Willard Interchange · Structure no. 3F 235

Built
1976
49 years old, rebuilt 2016
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
94 ft
1 main span
Daily traffic
67,875
2023 count
Owner
State
State Highway Agency

About this bridge

I-15 (SR-15) Sbl over SR-315 to Willard Bay is a prestressed concrete stringer/multi-beam or girder carrying I-15 (SR-15) Sbl over SR-315 to Willard Bay in Box Elder County, Utah. It was built in 1976 and reconstructed in 2016, so it is 49 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.

It carries about 67,875 vehicles a day, roughly 32% of them trucks, projected to reach 81,450 by 2043. The structure is 94 ft (28.8 m) long and 63 ft wide.

Location

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CarriesI-15 (SR-15) Sbl
CrossesSR-315 to Willard Bay
LocationWillard Interchange
RouteInterstate 15
CountyBox Elder County
StateUtah
Coordinates41.42194, -112.05306
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53.2 US tons
Inventory rating32.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length94 ft (28.8 m)
Longest span92 ft (28 m)
Deck width63 ft (19.1 m)
Roadway width41 ft (12.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic67,875 (2023)
Projected traffic81,450 by 2043
Trucks32%
Lanes on structure3
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 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 SR-315 to Willard Bay built?

It was built in 1976, making it 49 years old in 2025. It was reconstructed in 2016.

What condition is I-15 (SR-15) Sbl over SR-315 to Willard Bay 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) Sbl over SR-315 to Willard Bay carry?

About 67,875 vehicles per day (2023 count), of which roughly 32% are trucks.

How long is I-15 (SR-15) Sbl over SR-315 to Willard Bay?

The structure is 94 ft (28.8 m) long with a longest span of 92 ft (28 m) and a deck 63 ft wide.

Who owns I-15 (SR-15) Sbl over SR-315 to Willard Bay?

It is owned by the State Highway Agency.