US Bridges

State Route 1 over Pomponio Creek

Fair

San Mateo County, California · 04-SM-001-16.44 · Structure no. 35 0029

Built
1940
85 years old
Condition
Fair
inspected October 2024
Type
Culvert
Concrete Continuous
Length
32 ft
2 main spans
Daily traffic
6,100
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 1 over Pomponio Creek is a concrete continuous culvert carrying State Route 1 over Pomponio Creek in San Mateo County, California. It was built in 1940, so it is 85 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 6,100 vehicles a day, roughly 5% of them trucks, projected to reach 9,189 by 2046. The structure is 32 ft (9.8 m) long. If it were closed, the detour would be 11.2 mi (18 km).

Location

Open in Google Maps
CarriesState Route 1
CrossesPomponio Creek
Location04-SM-001-16.44
RouteState Highway 1
CountySan Mateo County
StateCalifornia
Coordinates37.29977, -122.4046
Functional classRural 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
Channel and channel protection8 Very GoodNo problems noted.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44.6 US tons
Inventory rating26.8 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadUnknown
Structure length32 ft (9.8 m)
Longest span14 ft (4.3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,100 (2009)
Projected traffic9,189 by 2046
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 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—
NavigationNo navigation control on waterway

Frequently asked questions

When was State Route 1 over Pomponio Creek built?

It was built in 1940, making it 85 years old in 2025.

What condition is State Route 1 over Pomponio Creek 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 over Pomponio Creek carry?

About 6,100 vehicles per day (2009 count), of which roughly 5% are trucks.

How long is State Route 1 over Pomponio Creek?

The structure is 32 ft (9.8 m) long with a longest span of 14 ft (4.3 m).

Who owns State Route 1 over Pomponio Creek?

It is owned by the State Highway Agency.