US Bridges

Willow Creek Road over Willow Creek

Good

Sonoma County, California · 1.45 MI E/O SR 1 · Structure no. 20C0570

Built
2011
14 years old
Condition
Good
inspected March 2022
Type
Slab
Prestressed Concrete
Length
48 ft
1 main span
Daily traffic
170
2010 count
Owner
County
County Highway Agency

About this bridge

Willow Creek Road over Willow Creek is a prestressed concrete slab carrying Willow Creek Road over Willow Creek in Sonoma County, California. It was built in 2011, so it is 14 years old, younger than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 170 vehicles a day, roughly 1% of them trucks, projected to reach 210 by 2040. The structure is 48 ft (14.6 m) long and 27 ft wide. If it were closed, the detour would be 31.7 mi (51 km).

Location

Open in Google Maps
CarriesWillow Creek Road
CrossesWillow Creek
Location1.45 MI E/O SR 1
RouteCounty Highway 0
CountySonoma County
StateCalifornia
Coordinates38.43507, -123.08691
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.4 US tons
Inventory rating35.7 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length48 ft (14.6 m)
Longest span46 ft (13.9 m)
Deck width27 ft (8.2 m)
Roadway width25 ft (7.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic170 (2010)
Projected traffic210 by 2040
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed31.7 mi (51 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Willow Creek Road over Willow Creek built?

It was built in 2011, making it 14 years old in 2025.

What condition is Willow Creek Road over Willow Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in March 2022.

How much traffic does Willow Creek Road over Willow Creek carry?

About 170 vehicles per day (2010 count), of which roughly 1% are trucks.

How long is Willow Creek Road over Willow Creek?

The structure is 48 ft (14.6 m) long with a longest span of 46 ft (13.9 m) and a deck 27 ft wide.

Who owns Willow Creek Road over Willow Creek?

It is owned by the County Highway Agency.