US Bridges

State Route 99 SB over Edgar Slough

Good

Butte County, California · 03-BUT-099-30.03 · Structure no. 12 0128L

Built
1989
36 years old
Condition
Good
inspected May 2023
Type
Slab
Concrete Continuous
Length
53 ft
3 main spans
Daily traffic
14,125
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 99 SB over Edgar Slough is a concrete continuous slab carrying State Route 99 SB over Edgar Slough in Butte County, California. It was built in 1989, so it is 36 years old, younger than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 14,125 vehicles a day, roughly 10% of them trucks, projected to reach 26,808 by 2045. The structure is 53 ft (16.2 m) long and 42 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesState Route 99 SB
CrossesEdgar Slough
Location03-BUT-099-30.03
RouteState Highway 99
Coordinates39.70841, -121.79399
Functional classUrban Principal Arterial - Other Freeway or Expressway

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating43.5 US tons
Inventory rating33.6 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadUnknown
Structure length53 ft (16.2 m)
Longest span21 ft (6.4 m)
Deck width42 ft (12.7 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic14,125 (2009)
Projected traffic26,808 by 2045
Trucks10%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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 99 SB over Edgar Slough built?

It was built in 1989, making it 36 years old in 2025.

What condition is State Route 99 SB over Edgar Slough in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in May 2023.

How much traffic does State Route 99 SB over Edgar Slough carry?

About 14,125 vehicles per day (2009 count), of which roughly 10% are trucks.

How long is State Route 99 SB over Edgar Slough?

The structure is 53 ft (16.2 m) long with a longest span of 21 ft (6.4 m) and a deck 42 ft wide.

Who owns State Route 99 SB over Edgar Slough?

It is owned by the State Highway Agency.