US Bridges

State Route 1 over San Carpoforo Creek

Fair

San Luis Obispo County, California · 05-SLO-001-71.34 · Structure no. 49 0055

Built
1956
69 years old
Condition
Fair
inspected September 2023
Type
Tee Beam
Concrete Continuous
Length
177 ft
4 main spans
Daily traffic
3,000
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 1 over San Carpoforo Creek is a concrete continuous tee beam carrying State Route 1 over San Carpoforo Creek in San Luis Obispo County, California. It was built in 1956, so it is 69 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 3,000 vehicles a day, projected to reach 3,557 by 2043. The structure is 177 ft (53.9 m) long and 32 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesState Route 1
CrossesSan Carpoforo Creek
Location05-SLO-001-71.34
RouteState Highway 1
CountySan Luis Obispo County
StateCalifornia
Coordinates35.76444, -121.31937
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating29.7 US tons
Inventory rating20.7 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length177 ft (53.9 m)
Longest span50 ft (15.2 m)
Deck width32 ft (9.8 m)
Roadway width28 ft (8.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,000 (2009)
Projected traffic3,557 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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 San Carpoforo Creek built?

It was built in 1956, making it 69 years old in 2025.

What condition is State Route 1 over San Carpoforo 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 September 2023.

How much traffic does State Route 1 over San Carpoforo Creek carry?

About 3,000 vehicles per day (2009 count).

How long is State Route 1 over San Carpoforo Creek?

The structure is 177 ft (53.9 m) long with a longest span of 50 ft (15.2 m) and a deck 32 ft wide.

Who owns State Route 1 over San Carpoforo Creek?

It is owned by the State Highway Agency.