US Bridges

South 23rd ST over Interstate 580

Fair

Contra Costa County, California · 04-CC-580-R2.89-RCH · Structure no. 28 0273

Built
1987
38 years old
Condition
Fair
inspected March 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete Continuous
Length
239 ft
2 main spans
Daily traffic
3,000
2016 count
Owner
State
State Highway Agency

About this bridge

South 23rd ST over Interstate 580 is a prestressed concrete continuous box beam or girders - multiple carrying South 23rd ST over Interstate 580 in Contra Costa County, California. It was built in 1987, so it is 38 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 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 3,000 vehicles a day, roughly 20% of them trucks, projected to reach 10,760 by 2042. The structure is 239 ft (72.8 m) long and 107 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesSouth 23rd ST
CrossesInterstate 580
Location04-CC-580-R2.89-RCH
RouteCity Street 0
CountyContra Costa County
StateCalifornia
Coordinates37.92154, -122.34732
Functional classUrban Minor Arterial

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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20 + Mod
Structure length239 ft (72.8 m)
Longest span120 ft (36.6 m)
Deck width107 ft (32.6 m)
Roadway width90 ft (27.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,000 (2016)
Projected traffic10,760 by 2042
Trucks20%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

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 South 23rd ST over Interstate 580 built?

It was built in 1987, making it 38 years old in 2025.

What condition is South 23rd ST over Interstate 580 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 March 2024.

How much traffic does South 23rd ST over Interstate 580 carry?

About 3,000 vehicles per day (2016 count), of which roughly 20% are trucks.

How long is South 23rd ST over Interstate 580?

The structure is 239 ft (72.8 m) long with a longest span of 120 ft (36.6 m) and a deck 107 ft wide.

Who owns South 23rd ST over Interstate 580?

It is owned by the State Highway Agency.