US Bridges

I-15 (SR-15) Nbl over SR-78 Intchg. X-Road

Fair

Juab County, Utah · At Mills Jct. Interchange · Structure no. 1F 435

Built
1985
40 years old
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
91 ft
1 main span
Daily traffic
17,450
2014 count
Owner
State
State Highway Agency

About this bridge

I-15 (SR-15) Nbl over SR-78 Intchg. X-Road is a prestressed concrete stringer/multi-beam or girder carrying I-15 (SR-15) Nbl over SR-78 Intchg. X-Road in Juab County, Utah. It was built in 1985, so it is 40 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 17,450 vehicles a day, roughly 37% of them trucks, projected to reach 21,813 by 2034. The structure is 91 ft (27.6 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
CrossesSR-78 Intchg. X-Road
LocationAt Mills Jct. Interchange
RouteInterstate 15
CountyJuab County
StateUtah
Coordinates39.48306, -111.97861
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.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating39.2 US tons
Inventory rating39.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length91 ft (27.6 m)
Longest span88 ft (26.8 m)
Deck width44 ft (13.4 m)
Roadway width41 ft (12.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic17,450 (2014)
Projected traffic21,813 by 2034
Trucks37%
Lanes on structure2
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
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 SR-78 Intchg. X-Road built?

It was built in 1985, making it 40 years old in 2025.

What condition is I-15 (SR-15) Nbl over SR-78 Intchg. X-Road 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) Nbl over SR-78 Intchg. X-Road carry?

About 17,450 vehicles per day (2014 count), of which roughly 37% are trucks.

How long is I-15 (SR-15) Nbl over SR-78 Intchg. X-Road?

The structure is 91 ft (27.6 m) long with a longest span of 88 ft (26.8 m) and a deck 44 ft wide.

Who owns I-15 (SR-15) Nbl over SR-78 Intchg. X-Road?

It is owned by the State Highway Agency.