US Bridges

I-15 (SR-15) Nbl over Co.Rd.(iowa String Rd)

Fair

Box Elder County, Utah · South Tremonton · Structure no. 1F 184

Built
1972
53 years old, rebuilt 2019
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
126 ft
3 main spans
Daily traffic
23,139
2017 count
Owner
State
State Highway Agency

About this bridge

I-15 (SR-15) Nbl over Co.Rd.(iowa String Rd) is a prestressed concrete stringer/multi-beam or girder carrying I-15 (SR-15) Nbl over Co.Rd.(iowa String Rd) in Box Elder County, Utah. It was built in 1972 and reconstructed in 2019, so it is 53 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 23,139 vehicles a day, roughly 35% of them trucks, projected to reach 27,767 by 2037. The structure is 126 ft (38.5 m) long and 44 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI-15 (SR-15) Nbl
CrossesCo.Rd.(iowa String Rd)
LocationSouth Tremonton
RouteInterstate 15
CountyBox Elder County
StateUtah
Coordinates41.69889, -112.18028
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 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 geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating45.3 US tons
Inventory rating26.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length126 ft (38.5 m)
Longest span61 ft (18.6 m)
Deck width44 ft (13.4 m)
Roadway width40 ft (12.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic23,139 (2017)
Projected traffic27,767 by 2037
Trucks35%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
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) Nbl over Co.Rd.(iowa String Rd) built?

It was built in 1972, making it 53 years old in 2025. It was reconstructed in 2019.

What condition is I-15 (SR-15) Nbl over Co.Rd.(iowa String Rd) 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) Nbl over Co.Rd.(iowa String Rd) carry?

About 23,139 vehicles per day (2017 count), of which roughly 35% are trucks.

How long is I-15 (SR-15) Nbl over Co.Rd.(iowa String Rd)?

The structure is 126 ft (38.5 m) long with a longest span of 61 ft (18.6 m) and a deck 44 ft wide.

Who owns I-15 (SR-15) Nbl over Co.Rd.(iowa String Rd)?

It is owned by the State Highway Agency.