US Bridges

I-15 (SR-15) Sbl over Santaquin Main ST

Fair

Utah County, Utah · Santaquin Interchange · Structure no. 3F 128

Built
1967
58 years old, rebuilt 2011
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
137 ft
3 main spans
Daily traffic
46,783
2023 count
Owner
State
State Highway Agency

About this bridge

I-15 (SR-15) Sbl over Santaquin Main ST is a prestressed concrete stringer/multi-beam or girder carrying I-15 (SR-15) Sbl over Santaquin Main ST in Utah County, Utah. It was built in 1967 and reconstructed in 2011, so it is 58 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 5 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 46,783 vehicles a day, roughly 23% of them trucks, projected to reach 56,140 by 2043. The structure is 137 ft (41.8 m) long and 40 ft wide.

Location

Open in Google Maps
CarriesI-15 (SR-15) Sbl
CrossesSantaquin Main ST
LocationSantaquin Interchange
RouteInterstate 15
CountyUtah County
StateUtah
Coordinates39.97579, -111.77237
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating41.8 US tons
Inventory rating23.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans3
Design loadHS 20 + Mod
Structure length137 ft (41.8 m)
Longest span59 ft (18 m)
Deck width40 ft (12.1 m)
Roadway width36 ft (11.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic46,783 (2023)
Projected traffic56,140 by 2043
Trucks23%
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 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 Santaquin Main ST built?

It was built in 1967, making it 58 years old in 2025. It was reconstructed in 2011.

What condition is I-15 (SR-15) Sbl over Santaquin Main ST 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 March 2023.

How much traffic does I-15 (SR-15) Sbl over Santaquin Main ST carry?

About 46,783 vehicles per day (2023 count), of which roughly 23% are trucks.

How long is I-15 (SR-15) Sbl over Santaquin Main ST?

The structure is 137 ft (41.8 m) long with a longest span of 59 ft (18 m) and a deck 40 ft wide.

Who owns I-15 (SR-15) Sbl over Santaquin Main ST?

It is owned by the State Highway Agency.