Thorn Hollow Road
Carrying Thorn Hollow Road over Whetstone Creek
0.03 Miles SE JCT 25860, Columbia, Washington
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: Thorn Hollow Road
The Thorn Hollow Road bridge in Columbia, Washington carries Thorn Hollow Road over Whetstone Creek. It was built in 2015, making it 11 years old today. The structure is built primarily of prestressed concrete and spans 1 section, stretching 12.8 meters (42 feet) end to end. Daily traffic averages 200 vehicles, placing it in the lower-traffic tier of Washington bridges. It is owned and maintained by County Highway Agency.
The latest FHWA inspection records show a deck rating of 8/9, superstructure at 8/9, substructure at 8/9. The weakest component sits in good condition. No reported major component scores in the Poor range under the current federal condition thresholds. Its NBI inventory load rating is 47.6 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How Thorn Hollow Road compares
Live comparison across Washington.
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 How the historical reference is calculated.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
- 2015
- Material
- Prestressed Concrete
- Number of Spans
- 1
- Structure Length
- 12.8 m (42 ft)
- Deck Width
- 8.5 m (28 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 200 vehicles/day
- Structure Number
- 088819000000000
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) is in good condition (8/9), showing no significant deterioration.
- • At 8/9, the superstructure (beams and supports above the deck) is in good shape and shows no significant wear.
- • The substructure (piers and abutments) is in good condition (8/9), showing no significant deterioration.
How to read this record
This page shows what the last federal inspection recorded, not whether Thorn Hollow 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 Thorn Hollow Road against other structures in Columbia and across Washington. Washington 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 Thorn Hollow Road?
Thorn Hollow Road in Columbia, Washington has a deck rating of 8/9, superstructure rating of 8/9, and substructure rating of 8/9 on the FHWA's 0–9 scale.
How often is Thorn Hollow Road inspected?
Thorn Hollow 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 200 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. Thorn Hollow Road 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 Thorn Hollow Road?
Thorn Hollow Road has an NBI inventory load rating of 47.6 metric tons.
Who is responsible for maintaining Thorn Hollow Road?
Thorn Hollow Road is owned and maintained by County Highway Agency.
How old is Thorn Hollow Road and does age affect safety?
Thorn Hollow Road was built in 2015, making it 11 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.