Interstate 280 over Hillside
GoodSan Mateo County, California · 04-SM-280-R21.55 · Structure no. 35 0320
- Built
- 1994
- 31 years old
- Condition
- Good
- inspected July 2023
- Type
- Slab
- Concrete Continuous
- Length
- 2,135 ft
- 49 main spans
- Daily traffic
- 101,000
- 2009 count
- Owner
- State
- State Highway Agency
About this bridge
Interstate 280 over Hillside is a concrete continuous slab carrying Interstate 280 over Hillside in San Mateo County, California. It was built in 1994, so it is 31 years old, younger than the California average of 54.8 years.
The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 101,000 vehicles a day, roughly 2% of them trucks, projected to reach 135,623 by 2040. The structure is 2,135 ft (650.6 m) long and 10 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| 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 280 over Hillside built?
It was built in 1994, making it 31 years old in 2025.
What condition is Interstate 280 over Hillside in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in July 2023.
How much traffic does Interstate 280 over Hillside carry?
About 101,000 vehicles per day (2009 count), of which roughly 2% are trucks.
How long is Interstate 280 over Hillside?
The structure is 2,135 ft (650.6 m) long with a longest span of 44 ft (13.4 m) and a deck 10 ft wide.
Who owns Interstate 280 over Hillside?
It is owned by the State Highway Agency.