US Bridges

State Route 1 over Russian Gulch

Fair

Sonoma County, California · 04-SON-001-24.50 · Structure no. 20 0070

Built
1940
85 years old
Condition
Fair
inspected June 2024
Type
Slab
Concrete Continuous
Length
105 ft
3 main spans
Daily traffic
2,225
2016 count
Owner
State
State Highway Agency

About this bridge

State Route 1 over Russian Gulch is a concrete continuous slab carrying State Route 1 over Russian Gulch in Sonoma 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 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 2,225 vehicles a day, projected to reach 4,873 by 2046. The structure is 105 ft (32 m) long and 31 ft wide. If it were closed, the detour would be 28 mi (45 km).

Location

Open in Google Maps
CarriesState Route 1
CrossesRussian Gulch
Location04-SON-001-24.50
RouteState Highway 1
CountySonoma County
StateCalifornia
Coordinates38.47067, -123.1536
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
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 geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating47.5 US tons
Inventory rating28.5 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 15
Structure length105 ft (32 m)
Longest span42 ft (12.8 m)
Deck width31 ft (9.4 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,225 (2016)
Projected traffic4,873 by 2046
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed28 mi (45 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 Russian Gulch built?

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

What condition is State Route 1 over Russian Gulch 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 June 2024.

How much traffic does State Route 1 over Russian Gulch carry?

About 2,225 vehicles per day (2016 count).

How long is State Route 1 over Russian Gulch?

The structure is 105 ft (32 m) long with a longest span of 42 ft (12.8 m) and a deck 31 ft wide.

Who owns State Route 1 over Russian Gulch?

It is owned by the State Highway Agency.