US Bridges

Interstate 15 SB over Route 8

Fair

San Diego County, California · 11-SD-015-R6.10-SD · Structure no. 57 0373L

Built
1960
65 years old, rebuilt 1993
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
311 ft
4 main spans
Daily traffic
100,000
2019 count
Owner
State
State Highway Agency

About this bridge

Interstate 15 SB over Route 8 is a prestressed concrete stringer/multi-beam or girder carrying Interstate 15 SB over Route 8 in San Diego County, California. It was built in 1960 and reconstructed in 1993, so it is 65 years old, older 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 100,000 vehicles a day, roughly 2% of them trucks, projected to reach 121,767 by 2041. The structure is 311 ft (94.8 m) long and 80 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesInterstate 15 SB
CrossesRoute 8
Location11-SD-015-R6.10-SD
RouteState Highway 15
CountySan Diego County
StateCalifornia
Coordinates32.77821, -117.11249
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionJuly 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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating43.2 US tons
Inventory rating24.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length311 ft (94.8 m)
Longest span83 ft (25.3 m)
Deck width80 ft (24.3 m)
Roadway width76 ft (23.3 m)
Vertical clearance over deck17 ft (5.3 m)

Traffic and service

Average daily traffic100,000 (2019)
Projected traffic121,767 by 2041
Trucks2%
Lanes on structure5
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 SB over Route 8 built?

It was built in 1960, making it 65 years old in 2025. It was reconstructed in 1993.

What condition is Interstate 15 SB over Route 8 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 July 2023.

How much traffic does Interstate 15 SB over Route 8 carry?

About 100,000 vehicles per day (2019 count), of which roughly 2% are trucks.

How long is Interstate 15 SB over Route 8?

The structure is 311 ft (94.8 m) long with a longest span of 83 ft (25.3 m) and a deck 80 ft wide.

Who owns Interstate 15 SB over Route 8?

It is owned by the State Highway Agency.