SOUTH THORP HWY
Carrying SOUTH THORP HWY over LIGHT DITCH
00.14 NW ROBINSON C, Kittitas, Washington
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
SOUTH THORP HWY in Kittitas, Washington sits above 18% of rated Washington bridges on inventory load rating (20 t), while its 1936 build year is earlier than 89% of Kittitas's recorded-year cohort (308 bridges).
SOUTH THORP HWY in Kittitas, Washington is rated Fair in the FHWA's 2024 National Bridge Inventory. Built in 1936, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 6. The lowest applicable rating sets the federal condition category, so this Fair 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 WA:083945000000000
PRE-1950 · CONCRETE · SINGLE-SPAN · TIED-CTRL · ARTERIAL-ADT · STANDARD-LOAD · CAT-FAIR
- PRE-1950 Pre-1950
- CONCRETE Concrete
- SINGLE-SPAN Single span
- TIED-CTRL Tied control
- ARTERIAL-ADT Arterial ADT
- STANDARD-LOAD Standard load
- CAT-FAIR Fair
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: SOUTH THORP HWY
The SOUTH THORP HWY bridge in Kittitas, Washington carries SOUTH THORP HWY over LIGHT DITCH. It was built in 1936, making it 90 years old today. It was last reconstructed in 1978, extending its service life. The structure is built primarily of concrete continuous and spans 1 section, stretching 9.1 meters (30 feet) end to end. Daily traffic averages 1,972 vehicles, placing it in the moderately-trafficked tier of Washington bridges. It is owned and maintained by County Highway Agency.
The latest FHWA inspection records show a deck rating of 7/9, superstructure at 6/9, substructure at 6/9. The weakest component sits in fair condition. None of this bridge's reported major components fall into the Poor condition range.
How SOUTH THORP HWY compares
Age against the county: built in 1936, earlier than 273 of Kittitas's 308 bridges with a recorded construction year (89%), against a county median build year of 1968. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across Washington bridges with a recorded inventory load rating (8,455 of 8,474 rated).
SOUTH THORP HWY vs every rated Washington bridge
Inventory load rating (metric tons), FHWA NBI, this state
20 Top 82% higher than 18% of 8,455 bridges
rated Washington 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.
Kittitas inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 308 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
- 1936
- Last Reconstructed
- 1978
- Material
- Concrete Continuous
- Number of Spans
- 1
- Structure Length
- 9.1 m (30 ft)
- Deck Width
- 9.8 m (32 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 1,972 vehicles/day
- Structure Number
- 083945000000000
Condition Analysis
- • The deck (driving surface) is in good condition (7/9), showing no significant deterioration.
- • The superstructure (beams and supports above the deck) rates fair at 6/9, minor deterioration that routine maintenance should address.
- • The substructure (piers and abutments) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
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 SOUTH THORP HWY 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 SOUTH THORP HWY against other structures in Kittitas 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 SOUTH THORP HWY?
SOUTH THORP HWY in Kittitas, Washington has a deck rating of 7/9, superstructure rating of 6/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.
How often is SOUTH THORP HWY inspected?
SOUTH THORP HWY'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 1,972 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. SOUTH THORP HWY 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 SOUTH THORP HWY?
SOUTH THORP HWY has an NBI inventory load rating of 20.4 metric tons.
Who is responsible for maintaining SOUTH THORP HWY?
SOUTH THORP HWY is owned and maintained by County Highway Agency.
How old is SOUTH THORP HWY and does age affect safety?
SOUTH THORP HWY was built in 1936, making it 90 years old and last reconstructed in 1978.
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.