NIESTRATH RD
Carrying NIESTRATH RD over SOUTH FORK GUALALA RIVER
JUST N FORT ROSS RD, Sonoma, California
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: NIESTRATH RD
The NIESTRATH RD bridge in Sonoma, California carries NIESTRATH RD over SOUTH FORK GUALALA RIVER. It was built in 1971, making it 55 years old today. The structure is built primarily of steel and spans 2 sections, stretching 18.3 meters (60 feet) end to end. Daily traffic averages 50 vehicles, placing it in the lower-traffic 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 5/9, substructure at 5/9. The weakest component sits in fair condition. No reported major component scores in the Poor range under the current federal condition thresholds. Its NBI inventory load rating is 30.1 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How NIESTRATH RD 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 How the historical reference is calculated.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
- 1971
- Material
- Steel
- Number of Spans
- 2
- Structure Length
- 18.3 m (60 ft)
- Deck Width
- 4.3 m (14 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 50 vehicles/day
- Structure Number
- 20C0437
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) rates good at 7/9, with no significant deterioration on file.
- • The superstructure (beams and supports above the deck) rates fair at 5/9, minor deterioration that routine maintenance should address.
- • The substructure (piers and abutments) rates fair at 5/9, minor deterioration that routine maintenance should address.
How to read this record
This page shows what the last federal inspection recorded, not whether NIESTRATH 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 NIESTRATH 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 NIESTRATH RD?
NIESTRATH RD in Sonoma, California has a deck rating of 7/9, superstructure rating of 5/9, and substructure rating of 5/9 on the FHWA's 0–9 scale.
How often is NIESTRATH RD inspected?
NIESTRATH 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 50 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. NIESTRATH RD is currently shown as Fair condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for NIESTRATH RD?
NIESTRATH RD has an NBI inventory load rating of 30.1 metric tons.
Who is responsible for maintaining NIESTRATH RD?
NIESTRATH RD is owned and maintained by County Highway Agency.
How old is NIESTRATH RD and does age affect safety?
NIESTRATH RD was built in 1971, making it 55 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.