US Bridges

State Route 1 over Arroyo Laguna

Fair

San Luis Obispo County, California · 05-SLO-001-R59.89 · Structure no. 49 0053

Built
1968
57 years old
Condition
Fair
inspected September 2023
Type
Tee Beam
Concrete Continuous
Length
112 ft
3 main spans
Daily traffic
2,200
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 1 over Arroyo Laguna is a concrete continuous tee beam carrying State Route 1 over Arroyo Laguna in San Luis Obispo County, California. It was built in 1968, so it is 57 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 2,200 vehicles a day, projected to reach 3,443 by 2045. The structure is 112 ft (34.1 m) long and 42 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesState Route 1
CrossesArroyo Laguna
Location05-SLO-001-R59.89
RouteState Highway 1
CountySan Luis Obispo County
StateCalifornia
Coordinates35.65324, -121.21927
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 above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating31.1 US tons
Inventory rating23.9 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length112 ft (34.1 m)
Longest span57 ft (17.4 m)
Deck width42 ft (12.8 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,200 (2009)
Projected traffic3,443 by 2045
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 Arroyo Laguna built?

It was built in 1968, making it 57 years old in 2025.

What condition is State Route 1 over Arroyo Laguna 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 Arroyo Laguna carry?

About 2,200 vehicles per day (2009 count).

How long is State Route 1 over Arroyo Laguna?

The structure is 112 ft (34.1 m) long with a longest span of 57 ft (17.4 m) and a deck 42 ft wide.

Who owns State Route 1 over Arroyo Laguna?

It is owned by the State Highway Agency.