US Bridges

State Route 29 NB over State RTE 121/IMOLA Ave

Fair

Napa County, California · 04-NAP-029-R10.38-NAP · Structure no. 21 0086R

Built
1961
64 years old
Condition
Fair
inspected April 2024
Type
Box Beam or Girders - Multiple
Concrete
Length
89 ft
1 main span
Daily traffic
29,500
2017 count
Owner
State
State Highway Agency

About this bridge

State Route 29 NB over State RTE 121/IMOLA Ave is a concrete box beam or girders - multiple carrying State Route 29 NB over State RTE 121/IMOLA Ave in Napa County, California. It was built in 1961, so it is 64 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 29,500 vehicles a day, roughly 6% of them trucks, projected to reach 3,912 by 2046. The structure is 89 ft (27.1 m) long and 40 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesState Route 29 NB
CrossesState RTE 121/IMOLA Ave
Location04-NAP-029-R10.38-NAP
RouteState Highway 29
CountyNapa County
StateCalifornia
Coordinates38.28183, -122.30018
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating63.6 US tons
Inventory rating48.9 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length89 ft (27.1 m)
Longest span89 ft (27.1 m)
Deck width40 ft (12.1 m)
Roadway width37 ft (11.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic29,500 (2017)
Projected traffic3,912 by 2046
Trucks6%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed3.1 mi (5 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 proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was State Route 29 NB over State RTE 121/IMOLA Ave built?

It was built in 1961, making it 64 years old in 2025.

What condition is State Route 29 NB over State RTE 121/IMOLA Ave 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 April 2024.

How much traffic does State Route 29 NB over State RTE 121/IMOLA Ave carry?

About 29,500 vehicles per day (2017 count), of which roughly 6% are trucks.

How long is State Route 29 NB over State RTE 121/IMOLA Ave?

The structure is 89 ft (27.1 m) long with a longest span of 89 ft (27.1 m) and a deck 40 ft wide.

Who owns State Route 29 NB over State RTE 121/IMOLA Ave?

It is owned by the State Highway Agency.