US Bridges

State Route 20 over Sutter Bypass

Poor

Sutter County, California · 03-SUT-020-4.22 · Structure no. 18 0005

Built
1938
87 years old, rebuilt 2000
Condition
Poor
inspected September 2023
Type
Slab
Concrete Continuous
Length
4,149 ft
197 main spans
Daily traffic
7,600
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 20 over Sutter Bypass is a concrete continuous slab carrying State Route 20 over Sutter Bypass in Sutter County, California. It was built in 1938 and reconstructed in 2000, so it is 87 years old, older than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 7,600 vehicles a day, projected to reach 11,524 by 2043. The structure is 4,149 ft (1,264.5 m) long and 44 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

Location

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CarriesState Route 20
CrossesSutter Bypass
Location03-SUT-020-4.22
RouteState Highway 20
CountySutter County
StateCalifornia
Coordinates39.14301, -121.84236
Functional classRural Principal Arterial - Other

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
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 rating40 US tons
Inventory rating23.9 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans197
Design loadHS 15
Structure length4,149 ft (1,264.5 m)
Longest span22 ft (6.7 m)
Deck width44 ft (13.3 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,600 (2009)
Projected traffic11,524 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$59.6 million (2020 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was State Route 20 over Sutter Bypass built?

It was built in 1938, making it 87 years old in 2025. It was reconstructed in 2000.

What condition is State Route 20 over Sutter Bypass in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in September 2023.

How much traffic does State Route 20 over Sutter Bypass carry?

About 7,600 vehicles per day (2009 count).

How long is State Route 20 over Sutter Bypass?

The structure is 4,149 ft (1,264.5 m) long with a longest span of 22 ft (6.7 m) and a deck 44 ft wide.

Who owns State Route 20 over Sutter Bypass?

It is owned by the State Highway Agency.