US Bridges

D ST-S280&S1 Onrmp over I 280 SULLIVAN-S280 Rmp

Fair

San Mateo County, California · 04-SM-280-R25.60-DLC · Structure no. 35 0315K

Built
1993
32 years old
Condition
Fair
inspected February 2025
Type
Box Beam or Girders - Multiple
Prestressed Concrete Continuous
Length
1,427 ft
10 main spans
Daily traffic
24,100
2005 count
Owner
State
State Highway Agency

About this bridge

D ST-S280&S1 Onrmp over I 280 SULLIVAN-S280 Rmp is a prestressed concrete continuous box beam or girders - multiple carrying D ST-S280&S1 Onrmp over I 280 SULLIVAN-S280 Rmp in San Mateo County, California. It was built in 1993, so it is 32 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 24,100 vehicles a day, roughly 2% of them trucks, projected to reach 31,308 by 2047. The structure is 1,427 ft (434.8 m) long and 40 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesD ST-S280&S1 Onrmp
CrossesI 280 SULLIVAN-S280 Rmp
Location04-SM-280-R25.60-DLC
RouteInterstate 280
CountySan Mateo County
StateCalifornia
Coordinates37.68302, -122.47197
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum 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 spans10
Design loadHS 20 + Mod
Structure length1,427 ft (434.8 m)
Longest span160 ft (48.8 m)
Deck width40 ft (12.3 m)
Roadway width36 ft (11 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic24,100 (2005)
Projected traffic31,308 by 2047
Trucks2%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
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 D ST-S280&S1 Onrmp over I 280 SULLIVAN-S280 Rmp built?

It was built in 1993, making it 32 years old in 2025.

What condition is D ST-S280&S1 Onrmp over I 280 SULLIVAN-S280 Rmp 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 D ST-S280&S1 Onrmp over I 280 SULLIVAN-S280 Rmp carry?

About 24,100 vehicles per day (2005 count), of which roughly 2% are trucks.

How long is D ST-S280&S1 Onrmp over I 280 SULLIVAN-S280 Rmp?

The structure is 1,427 ft (434.8 m) long with a longest span of 160 ft (48.8 m) and a deck 40 ft wide.

Who owns D ST-S280&S1 Onrmp over I 280 SULLIVAN-S280 Rmp?

It is owned by the State Highway Agency.