US Bridges

State Route 178 over Kern River

Fair

Kern County, California · 06-KER-178-R38.84 · Structure no. 50 0279

Built
1968
57 years old
Condition
Fair
inspected December 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
470 ft
3 main spans
Daily traffic
3,900
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 178 over Kern River is a steel continuous stringer/multi-beam or girder carrying State Route 178 over Kern River in Kern County, California. It was built in 1968, so it is 57 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 3,900 vehicles a day, projected to reach 8,610 by 2044. The structure is 470 ft (143.3 m) long and 62 ft wide. If it were closed, the detour would be 44.1 mi (71 km).

Location

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CarriesState Route 178
CrossesKern River
Location06-KER-178-R38.84
RouteState Highway 178
CountyKern County
StateCalifornia
Coordinates35.5878, -118.52643
Functional classRural Minor Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionDecember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating35.1 US tons
Inventory rating26.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length470 ft (143.3 m)
Longest span200 ft (61 m)
Deck width62 ft (18.9 m)
Roadway width60 ft (18.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,900 (2009)
Projected traffic8,610 by 2044
Trucks0%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed44.1 mi (71 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 State Route 178 over Kern River built?

It was built in 1968, making it 57 years old in 2025.

What condition is State Route 178 over Kern River 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 December 2024.

How much traffic does State Route 178 over Kern River carry?

About 3,900 vehicles per day (2009 count).

How long is State Route 178 over Kern River?

The structure is 470 ft (143.3 m) long with a longest span of 200 ft (61 m) and a deck 62 ft wide.

Who owns State Route 178 over Kern River?

It is owned by the State Highway Agency.