US Bridges

Bale Lane over Napa River

Fair

Napa County, California · 0.1 MI W Silverado Trail · Structure no. 21C0048

Built
1937
88 years old
Condition
Fair
inspected May 2024
Type
Truss - Thru
Steel
Length
104 ft
1 main span
Daily traffic
813
2014 count
Owner
County
County Highway Agency

About this bridge

Bale Lane over Napa River is a steel truss - thru carrying Bale Lane over Napa River in Napa County, California. It was built in 1937, so it is 88 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 813 vehicles a day, roughly 10% of them trucks, projected to reach 657 by 2042. The structure is 104 ft (31.7 m) long and 18 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesBale Lane
CrossesNapa River
Location0.1 MI W Silverado Trail
RouteCounty Highway 0
CountyNapa County
StateCalifornia
Coordinates38.55633, -122.5064
Functional classRural 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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating32.8 US tons
Inventory rating19.6 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckCorrugated steel
Main spans1
Design loadH 15
Structure length104 ft (31.7 m)
Longest span100 ft (30.5 m)
Deck width18 ft (5.5 m)
Roadway width17 ft (5.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic813 (2014)
Projected traffic657 by 2042
Trucks10%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 Bale Lane over Napa River built?

It was built in 1937, making it 88 years old in 2025.

What condition is Bale Lane over Napa River 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 Bale Lane over Napa River carry?

About 813 vehicles per day (2014 count), of which roughly 10% are trucks.

How long is Bale Lane over Napa River?

The structure is 104 ft (31.7 m) long with a longest span of 100 ft (30.5 m) and a deck 18 ft wide.

Who owns Bale Lane over Napa River?

It is owned by the County Highway Agency.