US Bridges

San Pedro Road over Interstate 280

Fair

San Mateo County, California · 04-SM-280-R25.78-DLC · Structure no. 35 0181

Built
1965
60 years old
Condition
Fair
inspected February 2025
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
446 ft
4 main spans
Daily traffic
25,000
2005 count
Owner
State
State Highway Agency

About this bridge

San Pedro Road over Interstate 280 is a concrete continuous box beam or girders - multiple carrying San Pedro Road over Interstate 280 in San Mateo County, California. It was built in 1965, so it is 60 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 25,000 vehicles a day, roughly 3% of them trucks, projected to reach 32,388 by 2043. The structure is 446 ft (136 m) long and 64 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesSan Pedro Road
CrossesInterstate 280
Location04-SM-280-R25.78-DLC
RouteCity Street 0D594
Coordinates37.68456, -122.47201
Functional classUrban Other Principal 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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Last inspectionFebruary 2025
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 geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating52.9 US tons
Inventory rating38.3 US tons

Structure

MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length446 ft (136 m)
Longest span155 ft (47.3 m)
Deck width64 ft (19.5 m)
Roadway width52 ft (15.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic25,000 (2005)
Projected traffic32,388 by 2043
Trucks3%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed1.2 mi (2 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 San Pedro Road over Interstate 280 built?

It was built in 1965, making it 60 years old in 2025.

What condition is San Pedro Road over Interstate 280 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 February 2025.

How much traffic does San Pedro Road over Interstate 280 carry?

About 25,000 vehicles per day (2005 count), of which roughly 3% are trucks.

How long is San Pedro Road over Interstate 280?

The structure is 446 ft (136 m) long with a longest span of 155 ft (47.3 m) and a deck 64 ft wide.

Who owns San Pedro Road over Interstate 280?

It is owned by the State Highway Agency.