US Bridges

County RD 306 over Salt Creek

Poor

Glenn County, California · 0.3 MI S of RD #200 · Structure no. 11C0057

Built
1948
77 years old
Condition
Poor
inspected August 2024
Type
Slab
Concrete Continuous
Length
102 ft
4 main spans
Daily traffic
300
2009 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 1948, so it is 77 years old, older than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 2 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 300 vehicles a day, roughly 10% of them trucks, projected to reach 355 by 2043. The structure is 102 ft (31.1 m) long and 29 ft wide. If it were closed, the detour would be 34.8 mi (56 km).

Location

Open in Google Maps
CarriesCounty RD 306
CrossesSalt Creek
Location0.3 MI S of RD #200
RouteCounty Highway 0
CountyGlenn County
StateCalifornia
Coordinates39.79013, -122.5193
Functional classRural Minor Collector

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure2 CriticalAdvanced deterioration of primary structural elements. Bridge may be closed until corrective action is taken.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2024
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourScour critical; extensive scour has occurred
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating37.5 US tons
Inventory rating22.5 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 15
Structure length102 ft (31.1 m)
Longest span30 ft (9.1 m)
Deck width29 ft (8.9 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic300 (2009)
Projected traffic355 by 2043
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed34.8 mi (56 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 1948, making it 77 years old in 2025.

What condition is County RD 306 over Salt Creek in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in August 2024.

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

About 300 vehicles per day (2009 count), of which roughly 10% are trucks.

How long is County RD 306 over Salt Creek?

The structure is 102 ft (31.1 m) long with a longest span of 30 ft (9.1 m) and a deck 29 ft wide.

Who owns County RD 306 over Salt Creek?

It is owned by the County Highway Agency.