US Bridges

County RD 306 over Salt Creek

Fair

Glenn County, California · 2.64 MI N Colusa CO Line · Structure no. 11C0156

Built
1930
95 years old, rebuilt 1950
Condition
Fair
inspected August 2023
Type
Slab
Concrete Continuous
Length
27 ft
2 main spans
Daily traffic
223
2011 count
Owner
County
County Highway Agency

About this bridge

County RD 306 over Salt Creek is a concrete continuous slab carrying County RD 306 over Salt Creek in Glenn County, California. It was built in 1930 and reconstructed in 1950, so it is 95 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 223 vehicles a day, roughly 15% of them trucks, projected to reach 332 by 2043. The structure is 27 ft (8.3 m) long and 31 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesCounty RD 306
CrossesSalt Creek
Location2.64 MI N Colusa CO Line
RouteCounty Highway 0
CountyGlenn County
StateCalifornia
Coordinates39.41857, -122.53719
Functional classRural Major Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2023
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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating29.7 US tons
Inventory rating17.9 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadUnknown
Structure length27 ft (8.3 m)
Longest span13 ft (4 m)
Deck width31 ft (9.3 m)
Roadway width29 ft (8.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic223 (2011)
Projected traffic332 by 2043
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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—
NavigationNo navigation control on waterway

Frequently asked questions

When was County RD 306 over Salt Creek built?

It was built in 1930, making it 95 years old in 2025. It was reconstructed in 1950.

What condition is County RD 306 over Salt 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 August 2023.

How much traffic does County RD 306 over Salt Creek carry?

About 223 vehicles per day (2011 count), of which roughly 15% are trucks.

How long is County RD 306 over Salt Creek?

The structure is 27 ft (8.3 m) long with a longest span of 13 ft (4 m) and a deck 31 ft wide.

Who owns County RD 306 over Salt Creek?

It is owned by the County Highway Agency.