US Bridges

Interstate 580 over San Pablo Bay

Fair

Contra Costa County, California · 04-CC-580-6.22-RCH · Structure no. 28 0100

Built
1956
69 years old
Condition
Fair
inspected December 2024
Type
Truss - Thru
Steel
Length
21,345 ft
6 main spans
Daily traffic
78,000
2022 count
Owner
State
State Highway Agency

About this bridge

Interstate 580 over San Pablo Bay is a steel truss - thru carrying Interstate 580 over San Pablo Bay in Contra Costa County, California. It was built in 1956, so it is 69 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 78,000 vehicles a day, roughly 5% of them trucks, projected to reach 132,622 by 2046. The structure is 21,345 ft (6,506 m) long and 78 ft wide. If it were closed, the detour would be 37.3 mi (60 km).

Location

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CarriesInterstate 580
CrossesSan Pablo Bay
Location04-CC-580-6.22-RCH
RouteInterstate 580
CountyContra Costa County
StateCalifornia
Coordinates37.93262, -122.40532
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionDecember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating30.8 US tons
Inventory rating23.6 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans6 (+103 approach)
Design loadHS 20
Structure length21,345 ft (6,506 m)
Longest span1,087 ft (331.3 m)
Deck width78 ft (23.8 m)
Roadway width70 ft (21.3 m)
Vertical clearance over deck16 ft (4.9 m)

Traffic and service

Average daily traffic78,000 (2022)
Projected traffic132,622 by 2046
Trucks5%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed37.3 mi (60 km)
TollToll bridge
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusEligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was Interstate 580 over San Pablo Bay built?

It was built in 1956, making it 69 years old in 2025.

What condition is Interstate 580 over San Pablo Bay 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 December 2024.

How much traffic does Interstate 580 over San Pablo Bay carry?

About 78,000 vehicles per day (2022 count), of which roughly 5% are trucks.

How long is Interstate 580 over San Pablo Bay?

The structure is 21,345 ft (6,506 m) long with a longest span of 1,087 ft (331.3 m) and a deck 78 ft wide.

Who owns Interstate 580 over San Pablo Bay?

It is owned by the State Highway Agency.