US Highway 101 NB over Caltrain UP RR Grand Onr
PoorSan Mateo County, California · 04-SM-101-21.92-SSF · Structure no. 35 0094R
- Built
- 1948
- 77 years old, rebuilt 1969
- Condition
- Poor
- inspected April 2023
- Type
- Stringer/Multi-beam or Girder
- Steel Continuous
- Length
- 728 ft
- 9 main spans
- Daily traffic
- 98,000
- 2009 count
- Owner
- State
- State Highway Agency
About this bridge
US Highway 101 NB over Caltrain UP RR Grand Onr is a steel continuous stringer/multi-beam or girder carrying US Highway 101 NB over Caltrain UP RR Grand Onr in San Mateo County, California. It was built in 1948 and reconstructed in 1969, so it is 77 years old, older than the California average of 54.8 years.
The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
It carries about 98,000 vehicles a day, roughly 4% of them trucks, projected to reach 121,559 by 2040. The structure is 728 ft (222 m) long and 57 ft wide. If it were closed, the detour would be 5 mi (8 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 4 Poor | Advanced section loss, deterioration, 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 US Highway 101 NB over Caltrain UP RR Grand Onr built?
It was built in 1948, making it 77 years old in 2025. It was reconstructed in 1969.
What condition is US Highway 101 NB over Caltrain UP RR Grand Onr in?
The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in April 2023.
How much traffic does US Highway 101 NB over Caltrain UP RR Grand Onr carry?
About 98,000 vehicles per day (2009 count), of which roughly 4% are trucks.
How long is US Highway 101 NB over Caltrain UP RR Grand Onr?
The structure is 728 ft (222 m) long with a longest span of 123 ft (37.4 m) and a deck 57 ft wide.
Who owns US Highway 101 NB over Caltrain UP RR Grand Onr?
It is owned by the State Highway Agency.