US Bridges

State Route 128 over Bidwell Creek

Fair

Sonoma County, California · 04-SON-128-24.01 · Structure no. 20 0044

Built
1977
48 years old
Condition
Fair
inspected November 2024
Type
Slab
Concrete Continuous
Length
71 ft
3 main spans
Daily traffic
2,650
2016 count
Owner
State
State Highway Agency

About this bridge

State Route 128 over Bidwell Creek is a concrete continuous slab carrying State Route 128 over Bidwell Creek in Sonoma County, California. It was built in 1977, so it is 48 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 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 2,650 vehicles a day, projected to reach 3,173 by 2046. The structure is 71 ft (21.6 m) long and 44 ft wide. If it were closed, the detour would be 19.9 mi (32 km).

Location

Open in Google Maps
CarriesState Route 128
CrossesBidwell Creek
Location04-SON-128-24.01
RouteState Highway 128
CountySonoma County
StateCalifornia
Coordinates38.6084, -122.65438
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating95.3 US tons
Inventory rating57.1 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length71 ft (21.6 m)
Longest span30 ft (9.1 m)
Deck width44 ft (13.3 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,650 (2016)
Projected traffic3,173 by 2046
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed19.9 mi (32 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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was State Route 128 over Bidwell Creek built?

It was built in 1977, making it 48 years old in 2025.

What condition is State Route 128 over Bidwell 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 November 2024.

How much traffic does State Route 128 over Bidwell Creek carry?

About 2,650 vehicles per day (2016 count).

How long is State Route 128 over Bidwell Creek?

The structure is 71 ft (21.6 m) long with a longest span of 30 ft (9.1 m) and a deck 44 ft wide.

Who owns State Route 128 over Bidwell Creek?

It is owned by the State Highway Agency.