US Bridges

Interstate 15 NB over Sierra Avenue

Fair

San Bernardino County, California · 08-SBD-015-12.84-FNA · Structure no. 54 0981R

Built
1976
49 years old
Condition
Fair
inspected February 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
162 ft
1 main span
Daily traffic
69,000
2019 count
Owner
State
State Highway Agency

About this bridge

Interstate 15 NB over Sierra Avenue is a prestressed concrete box beam or girders - multiple carrying Interstate 15 NB over Sierra Avenue in San Bernardino County, California. It was built in 1976, so it is 49 years old, younger than the California average of 54.8 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 69,000 vehicles a day, roughly 11% of them trucks, projected to reach 96,000 by 2040. The structure is 162 ft (49.4 m) long and 69 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesInterstate 15 NB
CrossesSierra Avenue
Location08-SBD-015-12.84-FNA
RouteInterstate 15
CountySan Bernardino County
StateCalifornia
Coordinates34.18123, -117.43684
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
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Last inspectionFebruary 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 geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating89.6 US tons
Inventory rating57.9 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length162 ft (49.4 m)
Longest span160 ft (48.8 m)
Deck width69 ft (20.9 m)
Roadway width65 ft (19.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic69,000 (2019)
Projected traffic96,000 by 2040
Trucks11%
Lanes on structure4
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 Interstate 15 NB over Sierra Avenue built?

It was built in 1976, making it 49 years old in 2025.

What condition is Interstate 15 NB over Sierra Avenue 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 Interstate 15 NB over Sierra Avenue carry?

About 69,000 vehicles per day (2019 count), of which roughly 11% are trucks.

How long is Interstate 15 NB over Sierra Avenue?

The structure is 162 ft (49.4 m) long with a longest span of 160 ft (48.8 m) and a deck 69 ft wide.

Who owns Interstate 15 NB over Sierra Avenue?

It is owned by the State Highway Agency.