US Bridges

SR 12 over Santa Rosa Creek

Fair

Sonoma County, California · 04-SON-012-21.45 · Structure no. 20 0028

Built
1974
51 years old
Condition
Fair
inspected September 2024
Type
Tee Beam
Concrete
Length
68 ft
1 main span
Daily traffic
41,250
2012 count
Owner
State
State Highway Agency

About this bridge

SR 12 over Santa Rosa Creek is a concrete tee beam carrying SR 12 over Santa Rosa Creek in Sonoma County, California. It was built in 1974, so it is 51 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 41,250 vehicles a day, roughly 4% of them trucks, projected to reach 44,116 by 2046. The structure is 68 ft (20.7 m) long and 84 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

Location

Open in Google Maps
CarriesSR 12
CrossesSanta Rosa Creek
Location04-SON-012-21.45
RouteState Highway 12
CountySonoma County
StateCalifornia
Coordinates38.45719, -122.6308
Functional classUrban Other Principal 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.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating69.7 US tons
Inventory rating50.7 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length68 ft (20.7 m)
Longest span66 ft (20.1 m)
Deck width84 ft (25.6 m)
Roadway width82 ft (25 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic41,250 (2012)
Projected traffic44,116 by 2046
Trucks4%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.9 mi (24 km)
TollOn a free road
National Highway SystemYes

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 SR 12 over Santa Rosa Creek built?

It was built in 1974, making it 51 years old in 2025.

What condition is SR 12 over Santa Rosa 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 September 2024.

How much traffic does SR 12 over Santa Rosa Creek carry?

About 41,250 vehicles per day (2012 count), of which roughly 4% are trucks.

How long is SR 12 over Santa Rosa Creek?

The structure is 68 ft (20.7 m) long with a longest span of 66 ft (20.1 m) and a deck 84 ft wide.

Who owns SR 12 over Santa Rosa Creek?

It is owned by the State Highway Agency.