US Bridges

N101-SIERRA Pt Off over Caltrain & UP RR

Fair

San Mateo County, California · 04-SM-101-23.66-BSBN · Structure no. 35 0130S

Built
1982
43 years old
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
909 ft
1 main span
Daily traffic
1,100
1998 count
Owner
State
State Highway Agency

About this bridge

N101-SIERRA Pt Off over Caltrain & UP RR is a prestressed concrete stringer/multi-beam or girder carrying N101-SIERRA Pt Off over Caltrain & UP RR in San Mateo County, California. It was built in 1982, so it is 43 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 6 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 1,100 vehicles a day, roughly 2% of them trucks, projected to reach 3,741 by 2040. The structure is 909 ft (277.1 m) long and 28 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesN101-SIERRA Pt Off
CrossesCaltrain & UP RR
Location04-SM-101-23.66-BSBN
RouteU.S. Route 101
CountySan Mateo County
StateCalifornia
Coordinates37.6715, -122.39076
Functional classUrban Principal Arterial - Other Freeway or Expressway

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1 (+7 approach)
Design loadHS 20 + Mod
Structure length909 ft (277.1 m)
Longest span134 ft (40.7 m)
Deck width28 ft (8.4 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,100 (1998)
Projected traffic3,741 by 2040
Trucks2%
Lanes on structure1
Traffic directionOne-way traffic
CarriesHighway
CrossesRailroad
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was N101-SIERRA Pt Off over Caltrain & UP RR built?

It was built in 1982, making it 43 years old in 2025.

What condition is N101-SIERRA Pt Off over Caltrain & UP RR 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 April 2023.

How much traffic does N101-SIERRA Pt Off over Caltrain & UP RR carry?

About 1,100 vehicles per day (1998 count), of which roughly 2% are trucks.

How long is N101-SIERRA Pt Off over Caltrain & UP RR?

The structure is 909 ft (277.1 m) long with a longest span of 134 ft (40.7 m) and a deck 28 ft wide.

Who owns N101-SIERRA Pt Off over Caltrain & UP RR?

It is owned by the State Highway Agency.