US Bridges

SR-99 Int.X-Rd. over I-15 (SR-15) Nbl & Sbl

Fair

Millard County, Utah · So.Fillmore Interchange · Structure no. 0C 580

Built
1972
53 years old
Condition
Fair
inspected February 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
254 ft
2 main spans
Daily traffic
2,690
2022 count
Owner
State
State Highway Agency

About this bridge

SR-99 Int.X-Rd. over I-15 (SR-15) Nbl & Sbl is a steel continuous stringer/multi-beam or girder carrying SR-99 Int.X-Rd. over I-15 (SR-15) Nbl & Sbl in Millard County, Utah. It was built in 1972, 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 2,690 vehicles a day, roughly 24% of them trucks, projected to reach 3,228 by 2042. The structure is 254 ft (77.4 m) long and 54 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

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CarriesSR-99 Int.X-Rd.
CrossesI-15 (SR-15) Nbl & Sbl
LocationSo.Fillmore Interchange
RouteState Highway 99
CountyMillard County
StateUtah
Coordinates38.9488, -112.35009
Functional classRural Major Collector

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 inspectionFebruary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating59 US tons
Inventory rating38.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20 + Mod
Structure length254 ft (77.4 m)
Longest span125 ft (38.1 m)
Deck width54 ft (16.4 m)
Roadway width51 ft (15.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,690 (2022)
Projected traffic3,228 by 2042
Trucks24%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

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 SR-99 Int.X-Rd. over I-15 (SR-15) Nbl & Sbl built?

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

What condition is SR-99 Int.X-Rd. over I-15 (SR-15) Nbl & Sbl 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 February 2023.

How much traffic does SR-99 Int.X-Rd. over I-15 (SR-15) Nbl & Sbl carry?

About 2,690 vehicles per day (2022 count), of which roughly 24% are trucks.

How long is SR-99 Int.X-Rd. over I-15 (SR-15) Nbl & Sbl?

The structure is 254 ft (77.4 m) long with a longest span of 125 ft (38.1 m) and a deck 54 ft wide.

Who owns SR-99 Int.X-Rd. over I-15 (SR-15) Nbl & Sbl?

It is owned by the State Highway Agency.