US Bridges

I-15 (SR-15) Sbl over Co.Rd. No.Of Summit Int.

Fair

Iron County, Utah · 0.7 Mi.No.Summit Intchg. · Structure no. 3F 281

Built
1973
52 years old
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
156 ft
3 main spans
Daily traffic
28,854
2023 count
Owner
State
State Highway Agency

About this bridge

I-15 (SR-15) Sbl over Co.Rd. No.Of Summit Int. is a prestressed concrete stringer/multi-beam or girder carrying I-15 (SR-15) Sbl over Co.Rd. No.Of Summit Int. in Iron County, Utah. It was built in 1973, so it is 52 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 28,854 vehicles a day, roughly 45% of them trucks, projected to reach 34,625 by 2043. The structure is 156 ft (47.6 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) Sbl
CrossesCo.Rd. No.Of Summit Int.
Location0.7 Mi.No.Summit Intchg.
RouteInterstate 15
CountyIron County
StateUtah
Coordinates37.80886, -112.93658
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 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 rating44 US tons
Inventory rating25.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length156 ft (47.6 m)
Longest span66 ft (20 m)
Deck width44 ft (13.4 m)
Roadway width40 ft (12.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic28,854 (2023)
Projected traffic34,625 by 2043
Trucks45%
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) Sbl over Co.Rd. No.Of Summit Int. built?

It was built in 1973, making it 52 years old in 2025.

What condition is I-15 (SR-15) Sbl over Co.Rd. No.Of Summit Int. 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 Co.Rd. No.Of Summit Int. carry?

About 28,854 vehicles per day (2023 count), of which roughly 45% are trucks.

How long is I-15 (SR-15) Sbl over Co.Rd. No.Of Summit Int.?

The structure is 156 ft (47.6 m) long with a longest span of 66 ft (20 m) and a deck 44 ft wide.

Who owns I-15 (SR-15) Sbl over Co.Rd. No.Of Summit Int.?

It is owned by the State Highway Agency.