US Bridges

NB State RTE 280 over Larkspur Drive

Fair

San Mateo County, California · 04-SM-280-R18.52-MLBR · Structure no. 35 0216R

Built
1969
56 years old
Condition
Fair
inspected July 2021
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
94 ft
1 main span
Daily traffic
51,500
2009 count
Owner
State
State Highway Agency

About this bridge

NB State RTE 280 over Larkspur Drive is a prestressed concrete box beam or girders - multiple carrying NB State RTE 280 over Larkspur Drive in San Mateo County, California. It was built in 1969, so it is 56 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 6 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 51,500 vehicles a day, projected to reach 70,297 by 2038. The structure is 94 ft (28.7 m) long and 70 ft wide.

Location

Open in Google Maps
CarriesNB State RTE 280
CrossesLarkspur Drive
Location04-SM-280-R18.52-MLBR
RouteInterstate 280
CountySan Mateo County
StateCalifornia
Coordinates37.59613, -122.41902
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionJuly 2021
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating110 US tons
Inventory rating35.7 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length94 ft (28.7 m)
Longest span92 ft (27.9 m)
Deck width70 ft (21.2 m)
Roadway width66 ft (20.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic51,500 (2009)
Projected traffic70,297 by 2038
Trucks0%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
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 proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was NB State RTE 280 over Larkspur Drive built?

It was built in 1969, making it 56 years old in 2025.

What condition is NB State RTE 280 over Larkspur Drive 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 July 2021.

How much traffic does NB State RTE 280 over Larkspur Drive carry?

About 51,500 vehicles per day (2009 count).

How long is NB State RTE 280 over Larkspur Drive?

The structure is 94 ft (28.7 m) long with a longest span of 92 ft (27.9 m) and a deck 70 ft wide.

Who owns NB State RTE 280 over Larkspur Drive?

It is owned by the State Highway Agency.