US Bridges

Southgate DR over Sonora Creek

Fair

Tuolumne County, California · South of RTE 49 · Structure no. 32C0075

Built
1940
85 years old
Condition
Fair
inspected May 2024
Type
Frame
Concrete
Length
31 ft
1 main span
Daily traffic
3,000
1985 count
Owner
City
City or Municipal Highway Agency

About this bridge

Southgate DR over Sonora Creek is a concrete frame carrying Southgate DR over Sonora Creek in Tuolumne County, California. It was built in 1940, so it is 85 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 3,000 vehicles a day, roughly 5% of them trucks, projected to reach 9,019 by 2046. The structure is 31 ft (9.4 m) long and 30 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesSouthgate DR
CrossesSonora Creek
LocationSouth of RTE 49
RouteCity Street 0
CountyTuolumne County
StateCalifornia
Coordinates37.97965, -120.38852
Functional classUrban Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
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 geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating35.4 US tons
Inventory rating21.4 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length31 ft (9.4 m)
Longest span29 ft (8.8 m)
Deck width30 ft (9.1 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,000 (1985)
Projected traffic9,019 by 2046
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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 Southgate DR over Sonora Creek built?

It was built in 1940, making it 85 years old in 2025.

What condition is Southgate DR over Sonora Creek 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 May 2024.

How much traffic does Southgate DR over Sonora Creek carry?

About 3,000 vehicles per day (1985 count), of which roughly 5% are trucks.

How long is Southgate DR over Sonora Creek?

The structure is 31 ft (9.4 m) long with a longest span of 29 ft (8.8 m) and a deck 30 ft wide.

Who owns Southgate DR over Sonora Creek?

It is owned by the City or Municipal Highway Agency.