US Bridges

68th Ave over Unnamed Slough

Fair

Tehama County, California · 1.0 MI E of SR 99 · Structure no. 08C0187

Built
1930
95 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
30 ft
2 main spans
Daily traffic
450
2010 count
Owner
County
County Highway Agency

About this bridge

68th Ave over Unnamed Slough is a steel continuous stringer/multi-beam or girder carrying 68th Ave over Unnamed Slough in Tehama 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.

It carries about 450 vehicles a day, roughly 1% of them trucks, projected to reach 544 by 2046. The structure is 30 ft (9.1 m) long and 18 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
Carries68th Ave
CrossesUnnamed Slough
Location1.0 MI E of SR 99
RouteCounty Highway 0
CountyTehama County
StateCalifornia
Coordinates40.11294, -122.09674
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
Deck7 GoodSome minor problems.
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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating69.3 US tons
Inventory rating41.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckCorrugated steel
Main spans2
Design loadUnknown
Structure length30 ft (9.1 m)
Longest span15 ft (4.6 m)
Deck width18 ft (5.5 m)
Roadway width18 ft (5.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic450 (2010)
Projected traffic544 by 2046
Trucks1%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 68th Ave over Unnamed Slough built?

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

What condition is 68th Ave over Unnamed 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 April 2024.

How much traffic does 68th Ave over Unnamed Slough carry?

About 450 vehicles per day (2010 count), of which roughly 1% are trucks.

How long is 68th Ave over Unnamed Slough?

The structure is 30 ft (9.1 m) long with a longest span of 15 ft (4.6 m) and a deck 18 ft wide.

Who owns 68th Ave over Unnamed Slough?

It is owned by the County Highway Agency.