Interstate 15 SB over National Ave
FairSan Diego County, California · 11-SD-015-R0.21L-SD · Structure no. 57 0742L
- Built
- 1978
- 47 years old
- Condition
- Fair
- inspected March 2023
- Type
- Box Beam or Girders - Single or Spread
- Prestressed Concrete
- Length
- 144 ft
- 1 main span
- Daily traffic
- 55,000
- 2019 count
- Owner
- State
- State Highway Agency
About this bridge
Interstate 15 SB over National Ave is a prestressed concrete box beam or girders - single or spread carrying Interstate 15 SB over National Ave in San Diego County, California. It was built in 1978, so it is 47 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 55,000 vehicles a day, roughly 2% of them trucks, projected to reach 68,500 by 2041. The structure is 144 ft (43.9 m) long and 54 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Interstate 15 SB over National Ave built?
It was built in 1978, making it 47 years old in 2025.
What condition is Interstate 15 SB over National Ave 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 Interstate 15 SB over National Ave carry?
About 55,000 vehicles per day (2019 count), of which roughly 2% are trucks.
How long is Interstate 15 SB over National Ave?
The structure is 144 ft (43.9 m) long with a longest span of 142 ft (43.3 m) and a deck 54 ft wide.
Who owns Interstate 15 SB over National Ave?
It is owned by the State Highway Agency.