SONOMA MTN RD
Carrying SONOMA MTN RD over MATANZAS CREEK
0.5 MI S BENNET VALLEY RD, Sonoma, California
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
SONOMA MTN RD in Sonoma, California sits above 7% of rated California bridges on inventory load rating (17 t), while its 1930 build year is earlier than 88% of Sonoma's recorded-year cohort (609 bridges).
SONOMA MTN RD in Sonoma, California is rated Good in the FHWA's 2024 National Bridge Inventory. Built in 1930, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 7. The lowest applicable rating sets the federal condition category, so this Good result describes the weakest reported component rather than the structure as a whole. No NBI category is a closure decision or a live crossing-safety verdict.
NBI record plate
Structure CA:20C0264
PRE-1950 · CONCRETE · SINGLE-SPAN · TIED-CTRL · ARTERIAL-ADT · LIGHT-LOAD · CAT-GOOD
- PRE-1950 Pre-1950
- CONCRETE Concrete
- SINGLE-SPAN Single span
- TIED-CTRL Tied control
- ARTERIAL-ADT Arterial ADT
- LIGHT-LOAD Light load
- CAT-GOOD Good
Inspection-sheet codes from this record’s year, material family, spans, controlling component, ADT, inventory load, and NBI category, not a live closure verdict.
Bridge Snapshot: SONOMA MTN RD
The SONOMA MTN RD bridge in Sonoma, California carries SONOMA MTN RD over MATANZAS CREEK. It was built in 1930, making it 96 years old today. It was last reconstructed in 1969, extending its service life. The structure is built primarily of concrete and spans 1 section, stretching 7.3 meters (24 feet) end to end. Daily traffic averages 1,400 vehicles, placing it in the moderately-trafficked tier of California bridges. It is owned and maintained by County Highway Agency.
The latest FHWA inspection records show a deck rating of 7/9, superstructure at 7/9, substructure at 7/9. The weakest component sits in good condition. All reported major components score above the Poor range.
How SONOMA MTN RD compares
Age against the county: built in 1930, earlier than 534 of Sonoma's 609 bridges with a recorded construction year (88%), against a county median build year of 1966. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across California bridges with a recorded inventory load rating (25,538 of 25,848 rated).
SONOMA MTN RD vs every rated California bridge
Inventory load rating (metric tons), FHWA NBI, this state
17 Top 93% higher than 7% of 25,538 bridges
rated California bridges, bucketed by value
Each bar is a band; taller bars hold more bridges. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source FHWA National Bridge Inventory · August 2026
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Reported 0–9 component ratings from the FHWA NBI. The highlighted component is the lowest reported input to this record’s current condition category; it is not a closure or live crossing-safety decision.
Sonoma inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 609 bridges in this county. Orthogonal to this structure's component profile above: a county catalog share, not a live crossing-safety verdict.
Structural Details
- Year Built
- 1930
- Last Reconstructed
- 1969
- Material
- Concrete
- Number of Spans
- 1
- Structure Length
- 7.3 m (24 ft)
- Deck Width
- 9.9 m (32 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 1,400 vehicles/day
- Structure Number
- 20C0264
Condition Analysis
- • The deck (driving surface) is in good condition (7/9), showing no significant deterioration.
- • The superstructure (beams and supports above the deck) is in good condition (7/9), showing no significant deterioration.
- • The substructure (piers and abutments) is in good condition (7/9), showing no significant deterioration.
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 SONOMA MTN RD 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 SONOMA MTN RD against other structures in Sonoma 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 SONOMA MTN RD?
SONOMA MTN RD in Sonoma, California has a deck rating of 7/9, superstructure rating of 7/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is SONOMA MTN RD inspected?
SONOMA MTN RD'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 1,400 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. SONOMA MTN RD is currently shown as Good condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for SONOMA MTN RD?
SONOMA MTN RD has an NBI inventory load rating of 17.2 metric tons.
Who is responsible for maintaining SONOMA MTN RD?
SONOMA MTN RD is owned and maintained by County Highway Agency.
How old is SONOMA MTN RD and does age affect safety?
SONOMA MTN RD was built in 1930, making it 96 years old and last reconstructed in 1969.
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.
Share this inspection record
Send this source-bounded record or download its data card. An NBI condition category is not a closure or live crossing-safety verdict.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Component ratings, ADT, and condition category on this page are copied from the NBI record for this structure; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.