US Bridges

I 280 N Al Line over 280/101 Interchange

Poor

San Francisco County, California · 04-SF-280-R4.16R-SF · Structure no. 34 0132R

Built
1960
65 years old, rebuilt 1996
Condition
Poor
inspected March 2024
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
1,140 ft
13 main spans
Daily traffic
170,000
2019 count
Owner
State
State Highway Agency

About this bridge

I 280 N Al Line over 280/101 Interchange is a concrete continuous box beam or girders - multiple carrying I 280 N Al Line over 280/101 Interchange in San Francisco County, California. It was built in 1960 and reconstructed in 1996, 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 170,000 vehicles a day, roughly 1% of them trucks, projected to reach 238,394 by 2044. The structure is 1,140 ft (347.5 m) long and 37 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

CarriesI 280 N Al Line
Crosses280/101 Interchange
Location04-SF-280-R4.16R-SF
RouteInterstate 280
Coordinates37.73412, -122.40966
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
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 spans13
Design loadHS 20
Structure length1,140 ft (347.5 m)
Longest span99 ft (30.2 m)
Deck width37 ft (11.4 m)
Roadway width31 ft (9.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic170,000 (2019)
Projected traffic238,394 by 2044
Trucks1%
Lanes on structure2
Traffic directionOne-way traffic
CarriesThird level (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$6.2 million (2024 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 280 N Al Line over 280/101 Interchange built?

It was built in 1960, making it 65 years old in 2025. It was reconstructed in 1996.

What condition is I 280 N Al Line 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 N Al Line over 280/101 Interchange carry?

About 170,000 vehicles per day (2019 count), of which roughly 1% are trucks.

How long is I 280 N Al Line over 280/101 Interchange?

The structure is 1,140 ft (347.5 m) long with a longest span of 99 ft (30.2 m) and a deck 37 ft wide.

Who owns I 280 N Al Line over 280/101 Interchange?

It is owned by the State Highway Agency.