Third Avenue over US Highway 101
FairSan Mateo County, California · 04-SM-101-13.46-SM · Structure no. 35 0026
- Built
- 1953
- 72 years old, rebuilt 1996
- Condition
- Fair
- inspected August 2023
- Type
- Tee Beam
- Concrete Continuous
- Length
- 310 ft
- 6 main spans
- Daily traffic
- 4,590
- 1998 count
- Owner
- State
- State Highway Agency
About this bridge
Third Avenue over US Highway 101 is a concrete continuous tee beam carrying Third Avenue over US Highway 101 in San Mateo County, California. It was built in 1953 and reconstructed in 1996, so it is 72 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 4,590 vehicles a day, roughly 7% of them trucks, projected to reach 15,015 by 2041. The structure is 310 ft (94.5 m) long and 103 ft wide. If it were closed, the detour would be 6.2 mi (10 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 | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Third Avenue over US Highway 101 built?
It was built in 1953, making it 72 years old in 2025. It was reconstructed in 1996.
What condition is Third Avenue over US Highway 101 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 August 2023.
How much traffic does Third Avenue over US Highway 101 carry?
About 4,590 vehicles per day (1998 count), of which roughly 7% are trucks.
How long is Third Avenue over US Highway 101?
The structure is 310 ft (94.5 m) long with a longest span of 67 ft (20.4 m) and a deck 103 ft wide.
Who owns Third Avenue over US Highway 101?
It is owned by the State Highway Agency.