US Bridges

State Route 1 SB over Clarendon Road

Fair

San Mateo County, California · 04-SM-001-R43.74-PFA · Structure no. 35 0021L

Built
1965
60 years old
Condition
Fair
inspected October 2024
Type
Tee Beam
Concrete Continuous
Length
125 ft
3 main spans
Daily traffic
16,250
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 1 SB over Clarendon Road is a concrete continuous tee beam carrying State Route 1 SB over Clarendon Road 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 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 16,250 vehicles a day, roughly 3% of them trucks, projected to reach 25,008 by 2046. The structure is 125 ft (38.1 m) long and 40 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesState Route 1 SB
CrossesClarendon Road
Location04-SM-001-R43.74-PFA
RouteState Highway 1
CountySan Mateo County
StateCalifornia
Coordinates37.62971, -122.48948
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Last inspectionOctober 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation8: Equal to present desirable criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50.4 US tons
Inventory rating35.7 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length125 ft (38.1 m)
Longest span63 ft (19.2 m)
Deck width40 ft (12.1 m)
Roadway width37 ft (11.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic16,250 (2009)
Projected traffic25,008 by 2046
Trucks3%
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 State Route 1 SB over Clarendon Road built?

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

What condition is State Route 1 SB over Clarendon Road 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 October 2024.

How much traffic does State Route 1 SB over Clarendon Road carry?

About 16,250 vehicles per day (2009 count), of which roughly 3% are trucks.

How long is State Route 1 SB over Clarendon Road?

The structure is 125 ft (38.1 m) long with a longest span of 63 ft (19.2 m) and a deck 40 ft wide.

Who owns State Route 1 SB over Clarendon Road?

It is owned by the State Highway Agency.