I-280 Southbound over Alpine RD & Los Trancos
FairSan Mateo County, California · 04-SM-280-R0.01 · Structure no. 35 0009L
- Built
- 1969
- 56 years old
- Condition
- Fair
- inspected October 2023
- Type
- Box Beam or Girders - Multiple
- Concrete Continuous
- Length
- 365 ft
- 4 main spans
- Daily traffic
- 46,500
- 2009 count
- Owner
- State
- State Highway Agency
About this bridge
I-280 Southbound over Alpine RD & Los Trancos is a concrete continuous box beam or girders - multiple carrying I-280 Southbound over Alpine RD & Los Trancos in San Mateo County, California. It was built in 1969, so it is 56 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 46,500 vehicles a day, projected to reach 68,037 by 2040. The structure is 365 ft (111.3 m) long and 80 ft wide.
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 | 7 Good | Some minor problems. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I-280 Southbound over Alpine RD & Los Trancos built?
It was built in 1969, making it 56 years old in 2025.
What condition is I-280 Southbound over Alpine RD & Los Trancos 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 October 2023.
How much traffic does I-280 Southbound over Alpine RD & Los Trancos carry?
About 46,500 vehicles per day (2009 count).
How long is I-280 Southbound over Alpine RD & Los Trancos?
The structure is 365 ft (111.3 m) long with a longest span of 92 ft (28 m) and a deck 80 ft wide.
Who owns I-280 Southbound over Alpine RD & Los Trancos?
It is owned by the State Highway Agency.