OLD SONOMA ROAD
Carrying OLD SONOMA ROAD over STATE ROUTE 29
04-NAP-029-10.70-NAP, Napa, California
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: OLD SONOMA ROAD
The OLD SONOMA ROAD bridge in Napa, California carries OLD SONOMA ROAD over STATE ROUTE 29. It was built in 1961, making it 65 years old today. The structure is built primarily of prestressed concrete. Daily traffic averages 59,000 vehicles, placing it in the heavily-trafficked tier of California bridges.
The latest FHWA inspection records show limited component ratings on file. The weakest component sits in unrated condition. All reported major components score above the Poor range.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How OLD SONOMA ROAD compares
Live comparison across California.
Historical Sufficiency Rating
PlainBridge-computedFHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Structural Details
- Year Built
- 1961
- Material
- Prestressed Concrete
- Avg Daily Traffic
- 59,000 vehicles/day
- Structure Number
- 21 0087
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
This page shows what the last federal inspection recorded, not whether OLD SONOMA ROAD is safe to cross today. Here is how to use it.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Learn how the 0–9 condition scale and Good/Fair/Poor categories are defined. How condition ratings work
- Compare OLD SONOMA ROAD against other structures in Napa and across California. California bridges
- Noticed visible damage or a safety concern? Report it to the agency that owns the bridge, or call 911 in an emergency. How to report a bridge
Condition codes come straight from the FHWA National Bridge Inventory and are not a real-time safety judgment. Only the owning agency, a state DOT, county, or other owner, can post, restrict, or close a bridge.
Frequently Asked Questions
What do the condition ratings mean for OLD SONOMA ROAD?
OLD SONOMA ROAD in Napa, California on the FHWA's 0–9 scale.
How often is OLD SONOMA ROAD inspected?
OLD SONOMA ROAD's responsible agency sets its routine interval under FHWA's risk-based inspection rules; this page does not expose the scheduled interval. It carries about 59,000 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. OLD SONOMA ROAD is currently shown as unrated condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for OLD SONOMA ROAD?
An inventory load rating is not recorded for OLD SONOMA ROAD.
Who is responsible for maintaining OLD SONOMA ROAD?
Ownership is not specified for OLD SONOMA ROAD in the NBI.
How old is OLD SONOMA ROAD and does age affect safety?
OLD SONOMA ROAD was built in 1961, making it 65 years old.
Disclaimer: Bridge condition data is from the FHWA NBI and reflects the last reported inspection. A Poor condition rating is not a live declaration that a bridge is closed or unsafe for travel. For current closure, posting, or safety information, contact the responsible transportation agency.
Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.