US Bridges

Dunaweal Lane over Napa River

Fair

Napa County, California · 0.2 MI N/E SH 29 · Structure no. 21C0025

Built
1965
60 years old
Condition
Fair
inspected May 2023
Type
Tee Beam
Concrete Continuous
Length
103 ft
2 main spans
Daily traffic
1,483
2014 count
Owner
County
County Highway Agency

About this bridge

Dunaweal Lane over Napa River is a concrete continuous tee beam carrying Dunaweal Lane over Napa River in Napa County, California. It was built in 1965, so it is 60 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 1,483 vehicles a day, roughly 10% of them trucks, projected to reach 1,924 by 2040. The structure is 103 ft (31.3 m) long and 32 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

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CarriesDunaweal Lane
CrossesNapa River
Location0.2 MI N/E SH 29
RouteCounty Highway 0
CountyNapa County
StateCalifornia
Coordinates38.56846, -122.55527
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
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 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 rating44.6 US tons
Inventory rating34.3 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length103 ft (31.3 m)
Longest span51 ft (15.6 m)
Deck width32 ft (9.9 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,483 (2014)
Projected traffic1,924 by 2040
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 Dunaweal Lane over Napa River built?

It was built in 1965, making it 60 years old in 2025.

What condition is Dunaweal 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 2023.

How much traffic does Dunaweal Lane over Napa River carry?

About 1,483 vehicles per day (2014 count), of which roughly 10% are trucks.

How long is Dunaweal Lane over Napa River?

The structure is 103 ft (31.3 m) long with a longest span of 51 ft (15.6 m) and a deck 32 ft wide.

Who owns Dunaweal Lane over Napa River?

It is owned by the County Highway Agency.