US Bridges

7 Mile Lane over Edgar Slough

Fair

Butte County, California · 1.1 MI N of Nelson RD · Structure no. 12C0057

Built
1956
69 years old
Condition
Fair
inspected February 2025
Type
Slab
Concrete Continuous
Length
73 ft
4 main spans
Daily traffic
710
2019 count
Owner
County
County Highway Agency

About this bridge

7 Mile Lane over Edgar Slough is a concrete continuous slab carrying 7 Mile Lane over Edgar Slough in Butte County, California. It was built in 1956, so it is 69 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 710 vehicles a day, roughly 13% of them trucks, projected to reach 998 by 2047. The structure is 73 ft (22.3 m) long and 32 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

Location

Open in Google Maps
Carries7 Mile Lane
CrossesEdgar Slough
Location1.1 MI N of Nelson RD
RouteCounty Highway 0
CountyButte County
StateCalifornia
Coordinates39.55945, -121.90877
Functional classRural Minor Collector

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 protection7 GoodSome minor problems.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating60.7 US tons
Inventory rating36.4 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length73 ft (22.3 m)
Longest span20 ft (6.1 m)
Deck width32 ft (9.9 m)
Roadway width32 ft (9.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic710 (2019)
Projected traffic998 by 2047
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.9 mi (24 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 7 Mile Lane over Edgar Slough built?

It was built in 1956, making it 69 years old in 2025.

What condition is 7 Mile Lane over Edgar 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 February 2025.

How much traffic does 7 Mile Lane over Edgar Slough carry?

About 710 vehicles per day (2019 count), of which roughly 13% are trucks.

How long is 7 Mile Lane over Edgar Slough?

The structure is 73 ft (22.3 m) long with a longest span of 20 ft (6.1 m) and a deck 32 ft wide.

Who owns 7 Mile Lane over Edgar Slough?

It is owned by the County Highway Agency.