US Bridges

County RD 306 over Corbin Creek

Fair

Glenn County, California · 17.64 MI N CO Line · Structure no. 11C0203

Built
1940
85 years old
Condition
Fair
inspected August 2023
Type
Culvert
Concrete Continuous
Length
26 ft
2 main spans
Daily traffic
563
2011 count
Owner
County
County Highway Agency

About this bridge

County RD 306 over Corbin Creek is a concrete continuous culvert carrying County RD 306 over Corbin Creek in Glenn County, California. It was built in 1940, so it is 85 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 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 563 vehicles a day, roughly 15% of them trucks, projected to reach 777 by 2043. The structure is 26 ft (7.9 m) long and 31 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesCounty RD 306
CrossesCorbin Creek
Location17.64 MI N CO Line
RouteCounty Highway 0
CountyGlenn County
StateCalifornia
Coordinates39.60827, -122.5351
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
Channel and channel protection8 Very GoodNo problems noted.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating30 US tons
Inventory rating17.9 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadUnknown
Structure length26 ft (7.9 m)
Longest span12 ft (3.7 m)
Deck width31 ft (9.4 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic563 (2011)
Projected traffic777 by 2043
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 Corbin Creek built?

It was built in 1940, making it 85 years old in 2025.

What condition is County RD 306 over Corbin 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 Corbin Creek carry?

About 563 vehicles per day (2011 count), of which roughly 15% are trucks.

How long is County RD 306 over Corbin Creek?

The structure is 26 ft (7.9 m) long with a longest span of 12 ft (3.7 m) and a deck 31 ft wide.

Who owns County RD 306 over Corbin Creek?

It is owned by the County Highway Agency.