US Bridges

Big Ranch Road over Salvador Overflow

Fair

Napa County, California · 0.3 MI N Trancas ST · Structure no. 21C0050

Built
1988
37 years old
Condition
Fair
inspected May 2024
Type
Slab
Prestressed Concrete
Length
70 ft
1 main span
Daily traffic
8,768
2017 count
Owner
County
County Highway Agency

About this bridge

Big Ranch Road over Salvador Overflow is a prestressed concrete slab carrying Big Ranch Road over Salvador Overflow in Napa County, California. It was built in 1988, so it is 37 years old, younger 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 8,768 vehicles a day, roughly 10% of them trucks, projected to reach 9,814 by 2042. The structure is 70 ft (21.3 m) long and 44 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesBig Ranch Road
CrossesSalvador Overflow
Location0.3 MI N Trancas ST
RouteCounty Highway 0
CountyNapa County
StateCalifornia
Coordinates38.32819, -122.28974
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMay 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating66.8 US tons
Inventory rating40.3 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length70 ft (21.3 m)
Longest span70 ft (21.3 m)
Deck width44 ft (13.4 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,768 (2017)
Projected traffic9,814 by 2042
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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 Big Ranch Road over Salvador Overflow built?

It was built in 1988, making it 37 years old in 2025.

What condition is Big Ranch Road over Salvador Overflow 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 Big Ranch Road over Salvador Overflow carry?

About 8,768 vehicles per day (2017 count), of which roughly 10% are trucks.

How long is Big Ranch Road over Salvador Overflow?

The structure is 70 ft (21.3 m) long with a longest span of 70 ft (21.3 m) and a deck 44 ft wide.

Who owns Big Ranch Road over Salvador Overflow?

It is owned by the County Highway Agency.