US Bridges

State Route 1 over Salmon Creek

Fair

Sonoma County, California · 04-SON-001-12.49 · Structure no. 20 0191

Built
1983
42 years old
Condition
Fair
inspected June 2024
Type
Slab
Concrete Continuous
Length
200 ft
5 main spans
Daily traffic
2,500
2016 count
Owner
State
State Highway Agency

About this bridge

State Route 1 over Salmon Creek is a concrete continuous slab carrying State Route 1 over Salmon Creek in Sonoma County, California. It was built in 1983, so it is 42 years old, younger 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 2,500 vehicles a day, roughly 2% of them trucks, projected to reach 5,619 by 2046. The structure is 200 ft (61 m) long and 44 ft wide. If it were closed, the detour would be 26.1 mi (42 km).

Location

Open in Google Maps
CarriesState Route 1
CrossesSalmon Creek
Location04-SON-001-12.49
RouteState Highway 1
CountySonoma County
StateCalifornia
Coordinates38.35218, -123.0613
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.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2024
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 geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length200 ft (61 m)
Longest span44 ft (13.4 m)
Deck width44 ft (13.3 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,500 (2016)
Projected traffic5,619 by 2046
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed26.1 mi (42 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 Salmon Creek built?

It was built in 1983, making it 42 years old in 2025.

What condition is State Route 1 over Salmon 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 June 2024.

How much traffic does State Route 1 over Salmon Creek carry?

About 2,500 vehicles per day (2016 count), of which roughly 2% are trucks.

How long is State Route 1 over Salmon Creek?

The structure is 200 ft (61 m) long with a longest span of 44 ft (13.4 m) and a deck 44 ft wide.

Who owns State Route 1 over Salmon Creek?

It is owned by the State Highway Agency.