US Bridges

State Route 70 over Slip Out

Fair

Butte County, California · 03-BUT-070-28.76 · Structure no. 12 0174

Built
1970
55 years old
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
298 ft
3 main spans
Daily traffic
2,550
2020 count
Owner
State
State Highway Agency

About this bridge

State Route 70 over Slip Out is a prestressed concrete continuous stringer/multi-beam or girder carrying State Route 70 over Slip Out in Butte County, California. It was built in 1970, so it is 55 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 2,550 vehicles a day, projected to reach 3,955 by 2041. The structure is 298 ft (90.8 m) long and 62 ft wide. If it were closed, the detour would be 66.5 mi (107 km).

Location

Open in Google Maps
CarriesState Route 70
CrossesSlip Out
Location03-BUT-070-28.76
RouteState Highway 70
CountyButte County
StateCalifornia
Coordinates39.66821, -121.52804
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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating36 US tons
Inventory rating27.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length298 ft (90.8 m)
Longest span100 ft (30.5 m)
Deck width62 ft (18.9 m)
Roadway width60 ft (18.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,550 (2020)
Projected traffic3,955 by 2041
Trucks0%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesOther
Detour if closed66.5 mi (107 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 70 over Slip Out built?

It was built in 1970, making it 55 years old in 2025.

What condition is State Route 70 over Slip Out 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 2023.

How much traffic does State Route 70 over Slip Out carry?

About 2,550 vehicles per day (2020 count).

How long is State Route 70 over Slip Out?

The structure is 298 ft (90.8 m) long with a longest span of 100 ft (30.5 m) and a deck 62 ft wide.

Who owns State Route 70 over Slip Out?

It is owned by the State Highway Agency.