US Bridges

Nelson RD over Edgar Slough

Fair

Butte County, California · 0.8 MI East of 7 Mile Lne · Structure no. 12C0174

Built
1966
59 years old
Condition
Fair
inspected January 2025
Type
Slab
Concrete Continuous
Length
58 ft
2 main spans
Daily traffic
640
2019 count
Owner
County
County Highway Agency

About this bridge

Nelson RD over Edgar Slough is a concrete continuous slab carrying Nelson RD over Edgar Slough in Butte County, California. It was built in 1966, so it is 59 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 640 vehicles a day, roughly 13% of them trucks, projected to reach 706 by 2042. The structure is 58 ft (17.7 m) long and 27 ft wide. If it were closed, the detour would be 13 mi (21 km).

Location

Open in Google Maps
CarriesNelson RD
CrossesEdgar Slough
Location0.8 MI East of 7 Mile Lne
RouteCounty Highway 0
CountyButte County
StateCalifornia
Coordinates39.55104, -121.89835
Functional classRural Major 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJanuary 2025
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 adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating65.4 US tons
Inventory rating39.2 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length58 ft (17.7 m)
Longest span28 ft (8.5 m)
Deck width27 ft (8.1 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic640 (2019)
Projected traffic706 by 2042
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed13 mi (21 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 Nelson RD over Edgar Slough built?

It was built in 1966, making it 59 years old in 2025.

What condition is Nelson RD 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 January 2025.

How much traffic does Nelson RD over Edgar Slough carry?

About 640 vehicles per day (2019 count), of which roughly 13% are trucks.

How long is Nelson RD over Edgar Slough?

The structure is 58 ft (17.7 m) long with a longest span of 28 ft (8.5 m) and a deck 27 ft wide.

Who owns Nelson RD over Edgar Slough?

It is owned by the County Highway Agency.