US Bridges

County Road 306 over Briscoe Creek

Good

Glenn County, California · 2.0 MI S of S.H. 162 · Structure no. 11C0183

Built
1956
69 years old
Condition
Good
inspected August 2023
Type
Tee Beam
Concrete Continuous
Length
135 ft
3 main spans
Daily traffic
251
2011 count
Owner
County
County Highway Agency

About this bridge

County Road 306 over Briscoe Creek is a concrete continuous tee beam carrying County Road 306 over Briscoe Creek in Glenn County, California. It was built in 1956, so it is 69 years old, older 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 251 vehicles a day, roughly 15% of them trucks, projected to reach 355 by 2043. The structure is 135 ft (41.1 m) long and 31 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesCounty Road 306
CrossesBriscoe Creek
Location2.0 MI S of S.H. 162
RouteCounty Highway 0
CountyGlenn County
StateCalifornia
Coordinates39.58807, -122.53814
Functional classRural Major Collector

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 inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating48.6 US tons
Inventory rating36.4 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length135 ft (41.1 m)
Longest span52 ft (15.8 m)
Deck width31 ft (9.6 m)
Roadway width31 ft (9.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic251 (2011)
Projected traffic355 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 Road 306 over Briscoe Creek built?

It was built in 1956, making it 69 years old in 2025.

What condition is County Road 306 over Briscoe 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 August 2023.

How much traffic does County Road 306 over Briscoe Creek carry?

About 251 vehicles per day (2011 count), of which roughly 15% are trucks.

How long is County Road 306 over Briscoe Creek?

The structure is 135 ft (41.1 m) long with a longest span of 52 ft (15.8 m) and a deck 31 ft wide.

Who owns County Road 306 over Briscoe Creek?

It is owned by the County Highway Agency.