US Bridges

I 280 - 101S (wu) over 280/101 Interchange

Poor

San Francisco County, California · 04-SF-101-1.48-SF · Structure no. 34 0070H

Built
1960
65 years old
Condition
Poor
inspected March 2024
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
902 ft
10 main spans
Daily traffic
80,000
2018 count
Owner
State
State Highway Agency

About this bridge

I 280 - 101S (wu) over 280/101 Interchange is a concrete continuous box beam or girders - multiple carrying I 280 - 101S (wu) over 280/101 Interchange in San Francisco County, California. It was built in 1960, so it is 65 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 80,000 vehicles a day, roughly 3% of them trucks, projected to reach 107,238 by 2041. The structure is 902 ft (274.9 m) long and 37 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

CarriesI 280 - 101S (wu)
Crosses280/101 Interchange
Location04-SF-101-1.48-SF
RouteU.S. Route 101
Coordinates37.72865, -122.4031
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Poor

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.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionMarch 2024
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 alignment8: Equal to present desirable criteria
Operating rating83.6 US tons
Inventory rating50.4 US tons

Structure

MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans10
Design loadHS 20
Structure length902 ft (274.9 m)
Longest span97 ft (29.5 m)
Deck width37 ft (11.4 m)
Roadway width34 ft (10.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic80,000 (2018)
Projected traffic107,238 by 2041
Trucks3%
Lanes on structure2
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$5.3 million (2024 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 280 - 101S (wu) over 280/101 Interchange built?

It was built in 1960, making it 65 years old in 2025.

What condition is I 280 - 101S (wu) over 280/101 Interchange 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 March 2024.

How much traffic does I 280 - 101S (wu) over 280/101 Interchange carry?

About 80,000 vehicles per day (2018 count), of which roughly 3% are trucks.

How long is I 280 - 101S (wu) over 280/101 Interchange?

The structure is 902 ft (274.9 m) long with a longest span of 97 ft (29.5 m) and a deck 37 ft wide.

Who owns I 280 - 101S (wu) over 280/101 Interchange?

It is owned by the State Highway Agency.