US Bridges

County RD 50 over Campbell Slough

FairPosted for load

Glenn County, California · 1/4 MI W CO RD Z · Structure no. 11C0072

Built
1930
95 years old
Condition
Fair
inspected August 2024
Type
Slab
Concrete Continuous
Length
492 ft
50 main spans
Daily traffic
72
2011 count
Owner
County
County Highway Agency

About this bridge

County RD 50 over Campbell Slough is a concrete continuous slab carrying County RD 50 over Campbell Slough in Glenn County, California. It was built in 1930, 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. Its operating status is: posted for load restriction.

It carries about 72 vehicles a day, roughly 10% of them trucks, projected to reach 87 by 2042. The structure is 492 ft (150 m) long and 16 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesCounty RD 50
CrossesCampbell Slough
Location1/4 MI W CO RD Z
RouteCounty Highway 0
CountyGlenn County
StateCalifornia
Coordinates39.5224, -121.9573
Functional classRural Local

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry7: Better than present minimum criteria
Waterway adequacy3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating17.9 US tons
Inventory rating10.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans50
Design loadUnknown
Structure length492 ft (150 m)
Longest span10 ft (3 m)
Deck width16 ft (4.9 m)
Roadway width15 ft (4.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic72 (2011)
Projected traffic87 by 2042
Trucks10%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 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 50 over Campbell Slough built?

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

What condition is County RD 50 over Campbell Slough 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 2024.

How much traffic does County RD 50 over Campbell Slough carry?

About 72 vehicles per day (2011 count), of which roughly 10% are trucks.

How long is County RD 50 over Campbell Slough?

The structure is 492 ft (150 m) long with a longest span of 10 ft (3 m) and a deck 16 ft wide.

Who owns County RD 50 over Campbell Slough?

It is owned by the County Highway Agency.